T. Rowe Price (TROW) 10-K 16 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2017	Feb. 14, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2,017
Entity Registrant Name	PRICE T ROWE GROUP INC
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 17.4
Entity Common Stock, Shares Outstanding (shares)		244,444,519
Entity Central Index Key	1,113,169
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 1,902,700	$ 1,204,900
Accounts receivable and accrued revenue	556,700	455,100
Investments	1,477,300	1,257,500
Assets of consolidated T. Rowe Price investment products ($1,446.1 million at December 31, 2016, and $1,839.6 million at December 31, 2017, related to variable interest entities)	2,048,400	1,680,500
Property and equipment, net	652,000	615,100
Goodwill	665,700	665,700
Other assets	231,900	346,200
Total assets	7,534,700	6,225,000
LIABILITIES
Accounts payable and accrued expenses	215,500	180,800
Liabilities of consolidated T. Rowe Price investment products ($56.8 million at December 31, 2016, and $39.5 million at December 31, 2017, related to variable interest entities)	55,900	65,600
Accrued compensation and related costs	108,500	92,600
Supplemental savings plan liability	269,300	150,900
Income taxes payable	68,300	39,300
Total liabilities	717,500	529,200
Commitments and contingent liabilities
Redeemable non-controlling interests	992,800	687,200
STOCKHOLDERS’ EQUITY
Preferred stock, undesignated, $.20 par value— authorized and unissued 20,000,000 shares	0	0
Common stock, $.20 par value—authorized 750,000,000; issued 244,784,000 shares at December 31, 2016, and 245,111,000 at December 31, 2017	49,000	49,000
Additional capital in excess of par value	846,100	654,500
Retained earnings	4,932,900	4,293,600
Accumulated other comprehensive income (loss)	(3,600)	11,500
Total permanent stockholders' equity	5,824,400	5,008,600
Total liabilities, redeemable non-controlling interests and permanent stockholders’ equity	$ 7,534,700	$ 6,225,000

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Assets of consolidated T. Rowe Price investment products	$ 2,048.4	$ 1,680.5
Liabilities of consolidated T. Rowe Price investment products	$ 55.9	$ 65.6
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.2	$ 0.2
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, par value (in dollars per share)	$ 0.2	$ 0.2
Common stock, shares authorized (in shares)	750,000,000	750,000,000
Common stock, shares outstanding (in shares)	245,111,000	244,784,000
Common stock, shares issued (in shares)	245,111,000	244,784,000
Variable interest entities [Member]
Assets of consolidated T. Rowe Price investment products	$ 1,839.6	$ 1,446.1
Liabilities of consolidated T. Rowe Price investment products	$ 39.5	$ 56.8

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues
Investment advisory fees		$ 4,287.7	$ 3,728.7	$ 3,687.3
Administrative fees		358.3	352.5	361.8
Distribution and servicing fees		147	141.7	151.5
Net revenues		4,793	4,222.9	4,200.6
Operating expenses
Compensation and related costs		1,664.9	1,494	1,443.6
Advertising and promotion		92	79.9	79.7
Distribution and servicing costs		147	141.7	151.5
Depreciation and amortization of property and equipment	[1]	143.6	133.4	126.3
Occupancy and facility costs		194.9	172.8	159.2
Other operating expenses		491.8	401.5	341.4
Nonrecurring charge (insurance recoveries) related to Dell appraisal rights matter		(50)	66.2	0
Total operating expenses		2,684.2	2,489.5	2,301.7
Net operating income		2,108.8	1,733.4	1,898.9
Non-operating income
Net investment income on investments not consolidated		198.3	108	105.3
Net investment income on consolidated T. Rowe Price investment products		193.9	121.1	1.5
Other income (expense)		4.1	(2)	(3.3)
Total non-operating income		396.3	227.1	103.5
Income before income taxes		2,505.1	1,960.5	2,002.4
Provision for income taxes		923.9	706.5	779.4
Net income	[1]	1,581.2	1,254	1,223
Less: net income attributable to redeemable non-controlling interests		83.4	39	0
Net income attributable to T. Rowe Price Group		$ 1,497.8	$ 1,215	$ 1,223
Earnings per share on common stock of T. Rowe Price Group
Basic (in dollars per share)		$ 6.07	$ 4.85	$ 4.74
Diluted (in dollars per share)		$ 5.97	$ 4.75	$ 4.63
[1]	See note 15 for a supplementary consolidating cash flow schedule.

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	[1]	$ 1,581.2	$ 1,254	$ 1,223
Other comprehensive income (loss)
Net unrealized holding gains (losses) on available-for-sale investments		37.4	(1)	(4.5)
Reclassification of (gains) and losses in accumulated other comprehensive income to non-operating investment income:
Capital gain distributions		(3.5)	(6)	(20.8)
Net gains realized on dispositions determined using average cost		(83.1)	(53)	(56.5)
Net unrealized gains recognized upon the transfer to trading investments		(23.6)	0	0
Other-than-temporary impairments		0	0	4.8
Total reclassification adjustments		(110.2)	(59)	(72.5)
Total net unrealized holding losses recognized in other comprehensive income		(72.8)	(60)	(77)
Total currency translation adjustments		68.9	(13.3)	(7.2)
Other comprehensive loss before income taxes		(3.9)	(73.3)	(84.2)
Net deferred tax benefits		10	28.2	34.4
Total other comprehensive income (loss)		6.1	(45.1)	(49.8)
Total comprehensive income		1,587.3	1,208.9	1,173.2
Less: comprehensive income attributable to redeemable non-controlling interests		104.6	36.5	0
Comprehensive income attributable to T. Rowe Price Group		1,482.7	1,172.4	1,173.2
Variable interest entities [Member]
Reclassification of (gains) and losses in accumulated other comprehensive income to non-operating investment income:
Consolidated T. Rowe Price investment products—variable interest entities		66.4	(9.5)	(4.9)
Reclassification losses (gains) recognized in non-operating investment income upon deconsolidation of certain T. Rowe Price investment products		(0.1)	(2.2)	5.8
Total currency translation adjustments		66.3	(11.7)	0.9
Equity method investments [Member]
Reclassification of (gains) and losses in accumulated other comprehensive income to non-operating investment income:
Total currency translation adjustments		$ 2.6	$ (1.6)	$ (8.1)
[1]	See note 15 for a supplementary consolidating cash flow schedule.

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities
Net income	[1]	$ 1,581.2	$ 1,254	$ 1,223
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation and amortization of property and equipment	[1]	143.6	133.4	126.3
Stock-based compensation expense	[1]	152	161.6	149
Realized gains on dispositions of available-for-sale T. Rowe Price investment products	[1]	(83.1)	(53)	(56.5)
Gains recognized upon transfer of an investment in a T. Rowe Price mutual fund from available-for-sale to held as trading	[1]	(23.6)	0	0
Net gains recognized on other investments	[1]	(49.7)	(31)	(5.9)
Investments in T. Rowe Price mutual funds held as trading to economically hedge supplemental savings plan liability	[1]	(218.6)	0	0
Net change in trading securities held by consolidated T. Rowe Price investment products	[1]	(1,492.9)	(1,297.9)	(7.5)
Changes in accounts receivable and accrued revenue	[1]	(100.8)	(9.3)	(3.2)
Changes in payables and accrued liabilities	[1]	323.4	138.6	98.2
Other changes in assets and liabilities	[1]	(2)	(125.9)	7.1
Net cash provided by (used in) operating activities	[1]	229.5	170.5	1,530.5
Cash flows from investing activities
Purchases of available-for-sale T. Rowe Price investment products	[1]	(16.9)	(0.1)	(164.8)
Dispositions of available-for-sale T. Rowe Price investment products	[1]	334.7	133.7	434.5
Net cash of T. Rowe Price investment products on consolidation (deconsolidation)	[1]	(64.2)	41.4	0
Additions to property and equipment	[1]	(186.1)	(148.3)	(151.3)
Other investing activity	[1]	(28.5)	79.5	(9.4)
Net cash provided by (used in) investing activities	[1]	39	106.2	109
Cash flows from financing activities
Repurchases of common stock	[1]	(458.1)	(676.9)	(987.8)
Common share issuances under stock-based compensation plans	[1]	201.1	126.3	73.5
Dividends paid to common stock and equity-award holders	[1]	(563.1)	(540.8)	(1,059)
Net subscriptions received from redeemable non-controlling interest holders	[1]	1,281.6	915	0
Net cash (used in) provided by financing activities	[1]	461.5	(176.4)	(1,973.3)
Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products	[1]	5.3	(2.1)	0
Net change in cash and cash equivalents during period	[1]	735.3	98.2	(333.8)
Cash and cash equivalents at beginning of year	[1]	1,270.5	1,172.3	1,506.1
Cash and cash equivalents at end of year	[1]	$ 2,005.8	$ 1,270.5	$ 1,172.3
[1]	See note 15 for a supplementary consolidating cash flow schedule.

CONSOLIDATED STATEMENTS OF CAS7

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Cash and cash equivalents	$ 1,902.7	$ 1,204.9
Consolidated T. Rowe Price investment products [Member]
Cash and cash equivalents	$ 103.1	$ 65.6

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common stock [Member]	Additional capital in excess of par value [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss) [Member]	Restricted shares [Member]	Restricted shares [Member]Common stock [Member]	Restricted shares [Member]Additional capital in excess of par value [Member]	Restricted stock units [Member]	Restricted stock units [Member]Common stock [Member]	Restricted stock units [Member]Additional capital in excess of par value [Member]	New accounting pronouncement, early adoption, effect [Member]	New accounting pronouncement, early adoption, effect [Member]Additional capital in excess of par value [Member]	New accounting pronouncement, early adoption, effect [Member]Retained earnings [Member]
Balances (in shares) at Dec. 31, 2014		261,110
Balances at Dec. 31, 2014	$ 5,395,200	$ 52,200	$ 756,500	$ 4,450,100	$ 136,400
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,223,000			1,223,000
Other comprehensive income (loss), net of tax	(49,800)				(49,800)
Dividends declared	(1,059,000)			(1,059,000)
Common stock-based compensation plans activity
Shares issued upon option exercises (shares)		2,471
Shares issued upon option exercises	84,500	$ 500	84,000
Shares issued, net of shares withheld for taxes (shares)							(180)			236
Shares issued, net of shares withheld for taxes						$ (14,300)		$ (14,300)	$ (2,000)		$ (2,000)
Forfeiture of restricted awards (shares)		(59)
Net tax benefits	23,200		23,200
Stock-based compensation expense	149,000		149,000
Restricted stock units issued as dividend equivalents	0		200	(200)
Common shares repurchased (shares)		(13,109)
Common shares repurchased	(987,800)	$ (2,600)	(342,000)	(643,200)
Balances (in shares) at Dec. 31, 2015		250,469
Balances at Dec. 31, 2015	4,762,000	$ 50,100	654,600	3,970,700	86,600
Beginning balances attributable to redeemable non-controlling interests at Dec. 31, 2014	0
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income attributable to redeemable non-controlling interests	0
Ending balances attributable to redeemable non-controlling interests at Dec. 31, 2015	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adopting new accounting guidance | Accounting standards update 2015-2 [Member]				32,500	(32,500)
Cumulative effect of adopting new accounting guidance | Accounting standards update 2016-9 [Member]												$ 3,900	$ 12,900	$ (9,000)
Balances, Adjusted	4,765,900	$ 50,100	667,500	3,994,200	54,100
Balances, Adjusted | Accounting standards update 2015-2 [Member]					54,100
Increase (Decrease) in Temporary Equity [Roll Forward]
Reclassification of T. Rowe Price investment products upon adoption of new accounting guidance on January 1, 2016 | Accounting standards update 2015-2 [Member]	672,700
Balances attributable to redeemable non-controlling interest, adjusted	672,700
Net income	1,215,000			1,215,000
Other comprehensive income (loss), net of tax	(42,600)				(42,600)
Dividends declared	(541,200)			(541,200)
Shares issued upon option exercises (shares)		4,140
Shares issued upon option exercises	149,500	$ 800	148,700
Shares issued, net of shares withheld for taxes (shares)							(178)			409
Shares issued, net of shares withheld for taxes						(14,000)		(14,000)	(8,700)	$ 100	(8,800)
Forfeiture of restricted awards (shares)		(61)
Stock-based compensation expense	161,600		161,600
Restricted stock units issued as dividend equivalents	0		100	(100)
Common shares repurchased (shares)		(9,995)
Common shares repurchased	(676,900)	$ (2,000)	(300,600)	(374,300)
Balances (in shares) at Dec. 31, 2016		244,784
Balances at Dec. 31, 2016	5,008,600	$ 49,000	654,500	4,293,600	11,500
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income attributable to redeemable non-controlling interests	39,000
Other comprehensive loss, net of tax, attributable to reedemable non-controlling interests	(2,500)
Net subscriptions into T. Rowe Price investment products	945,300
Net deconsolidations of T. Rowe Price investment products	(967,300)
Ending balances attributable to redeemable non-controlling interests at Dec. 31, 2016	687,200
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,497,800			1,497,800
Other comprehensive income (loss), net of tax	(15,100)				(15,100)
Dividends declared	(562,600)			(562,600)
Common stock-based compensation plans activity
Shares issued upon option exercises (shares)		6,339
Shares issued upon option exercises	252,200	$ 1,200	251,000
Shares issued, net of shares withheld for taxes (shares)							(170)			789
Shares issued, net of shares withheld for taxes						$ (19,200)		$ (19,200)	$ (31,200)	$ 100	$ (31,300)
Forfeiture of restricted awards (shares)		(19)
Forfeiture of restricted awards	0	$ 0	0
Stock-based compensation expense	152,000		152,000
Restricted stock units issued as dividend equivalents	0		200	(200)
Common shares repurchased (shares)		(6,612)
Common shares repurchased	(458,100)	$ (1,300)	(161,100)	(295,700)
Balances (in shares) at Dec. 31, 2017		245,111
Balances at Dec. 31, 2017	5,824,400	$ 49,000	$ 846,100	$ 4,932,900	$ (3,600)
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income attributable to redeemable non-controlling interests	83,400
Other comprehensive loss, net of tax, attributable to reedemable non-controlling interests	21,200
Net subscriptions into T. Rowe Price investment products	1,243,700
Net deconsolidations of T. Rowe Price investment products	(1,042,700)
Ending balances attributable to redeemable non-controlling interests at Dec. 31, 2017	$ 992,800

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES.	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES. T. Rowe Price Group, Inc. derives its consolidated revenues and net income primarily from investment advisory services that its subsidiaries provide to individual and institutional investors in the T. Rowe Price U.S. mutual funds and other investment products , including separately managed accounts, subadvised funds, and other T. Rowe Price products . We also provide our investment advisory clients with related administrative services, including distribution, mutual fund transfer agent, accounting and shareholder services; participant recordkeeping and transfer agent services for defined contribution retirement plans; brokerage, and trust services. Investment advisory revenues depend largely on the total value and composition of assets under our management. Accordingly, fluctuations in financial markets and in the composition of assets under management impact our revenues and results of operations. BASIS OF PREPARATION. These consolidated financial statements have been prepared by our management in accordance with accounting principles generally accepted in the United States. These principles require that we make certain estimates and assumptions. Actual results may vary from our estimates. In 2017, we recognized in our income tax provision a non-recurring charge of $71.1 million to reflect the estimated effect of the U.S. tax law changes enacted on December 22, 2017. The charge is a reasonable estimate based on current interpretation of the tax law changes and includes $18.9 million for the remeasurement of our deferred tax assets and liabilities, and a $52.2 million tax liability for the mandatory deemed repatriation of foreign sourced net earnings. We will continue to evaluate the impact of the tax law changes on our estimates and expectations due to changes in our interpretations of the law, assumptions used in applying the law, and additional guidance concerning the law that may be issued. We will report any applicable adjustments to these estimates in 2018 after our estimates are finalized. Refer to Note 7 for more information on the impact of tax reform on our 2017 financial statements and effective tax rate. NEWLY ISSUED BUT NOT YET ADOPTED ACCOUNTING GUIDANCE. In May 2014, the FASB issued Accounting Standards Update No. 2014-09 — Revenue from Contracts with Customers, and subsequently has issued several related accounting standard updates clarifying several aspects of ASU 2014-09, including technical corrections and improvements (ASC 606). The standard update provides a single, comprehensive revenue recognition model for all contracts with customers to improve comparability within industries, across industries, and across capital markets. It contains principles to apply to determine the measurement of revenue and the timing of when it is recognized. We will adopt the new standard on its effective date, January 1, 2018, using the retrospective approach with adjustments to each prior period. We concluded that the new standards do not materially change the timing of revenue recognition. However, the presentation of certain revenue related expenses totaling about $60 million in 2016 and 2017 will change from being recognized net against the related revenues to being reported within operating expenses. Additionally, we plan to enhance disclosures in accordance with the standard's disclosure requirements in 2018. In January 2016, the FASB issued Accounting Standards Update No. 2016-01 — Financial Instruments — Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. This standard update addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments and requires a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. We will adopt the new standard on its effective date, January 1, 2018. Upon adoption, we will reclassify net unrealized holding gains recognized on investments in T. Rowe Price products totaling $7.9 million from accumulated other comprehensive income to retained earnings. After January 1, 2018, the change in the fair value of investments in T. Rowe Price investment product s previously accounted for as available-for-sale investments will be recognized in our consolidated income statement rather than our consolidated statement of comprehensive income. The impact upon implementation of the standard on our investments without a readily determinable fair value is not material. In February 2016, the FASB issued Accounting Standards Update No. 2016-02 — Leases (Topic 842). The standard update seeks to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The standards update is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. We are currently evaluating the impact this standard will have on our financial position and results of operations. We have considered all other newly issued accounting guidance that is applicable to our operations and the preparation of our consolidated financial statements, including guidance which we have not yet adopted. We do not believe that any such guidance will have a material effect on our financial position or results of operation. CONSOLIDATION. Our consolidated financial statements include the accounts of all subsidiaries and T. Rowe Price investment products in which we have a controlling interest. We are generally deemed to have a controlling interest when we own the majority of a voting interest entity (VOE) or are deemed to be the primary beneficiary of a variable interest entity (VIE). We perform an analysis of our investments to determine if the investment entity is a VOE or VIE. Our analysis involves judgment and considers several factors, including an entity’s legal organization, capital structure, the rights of the equity investment holders, our ownership interest in the entity, and our contractual involvement with the entity. We continually review and reconsider our VOE or VIE conclusions upon the occurrence of certain events, such as changes to our ownership interest, changes to an entity’s legal structure, or amendments to governing documents. Upon consolidation of T. Rowe Price investment products , we retain the specialized investment company accounting principles of the underlying funds. All material accounts and transactions between consolidated entities are eliminated in consolidation. Variable interest entities VIEs are entities that, by design: (i ) lack sufficient equity to permit the entity to finance its activities independently or (ii) have equity holders that do not have the power to direct the activities of the entity that most significantly impact the entity’s economic performance, the obligation to absorb the entity’s losses, or the rights to receive the entity’s residual returns. We consolidate a VIE when we are the primary beneficiary, which is the party that has both (i) the power to direct the activities of the VIE that most significantly impact its economic performance and (ii) the obligation to absorb losses of the entity or the right to receive benefits from the VIE that could potentially be significant. Our Luxembourg-based SICAV funds and other T. Rowe Price investment products regulated outside the U.S. were determined to be VIEs. Along with VIEs that we consolidate, we also hold variable interests in other VIEs, including several investment partnerships that are not consolidated because we are not the primary beneficiary. Redeemable non-controlling interests We recognize redeemable non-controlling interests for the portion of the net assets of our consolidated T. Rowe Price investment products held by unrelated third-party investors as their interest is convertible to cash and other assets at their option. As such, we reflect redeemable non-controlling interests as temporary equity in our consolidated balance sheets. Investments in T. Rowe Price money market mutual funds We do not consider our investments in T. Rowe Price money market mutual funds when performing our consolidation analysis as the guidance provides a scope exception for interests in entities that are required to comply with, or operate in accordance with, requirements similar to those in Rule 2a-7 of the Investment Company Act of 1940 for registered money market funds. CASH EQUIVALENTS. Cash equivalents consist primarily of short-term, highly liquid investments in T. Rowe Price money market mutual funds . The cost of these funds is equivalent to fair value. INVESTMENTS. T. Rowe Price investment products that are accounted for as available-for-sale investments have been made for both general corporate investment purposes and to provide seed capital for newly formed product s. These investments are carried at fair value using the quoted closing net asset value (NAV) per share of each fund as of the balance sheet date. Changes in net unrealized holding gains or losses on these investments are recognized in other comprehensive income. We review the carrying amount of each investment on a quarterly basis and recognize an impairment charge in non-operating investment income whenever an unrealized loss is considered other than temporary. In determining whether a holding is other-than-temporarily impaired, we consider various factors, including the duration of time it has existed, the severity of the impairment, any subsequent changes in value, and our intent and ability to hold the investment for a period of time sufficient for an anticipated recovery in fair value. Subject to the other considerations noted above, we believe a holding with an unrealized loss that has persisted daily throughout the six months between quarter-ends is generally presumed to have an other-than-temporary impairment. We may also recognize an other-than-temporary impairment if particular circumstances of the underlying investment do not warrant our belief that a near-term recovery is possible. Equity method investments consist of investments in entities, including T. Rowe Price investment products , for which we have the ability to exercise significant influence over the operating and financial policies of the investee. The carrying values of these investments are adjusted to reflect our proportionate share of the investee's net income or loss, any unrealized gain or loss resulting from the translation of foreign-denominated financial statements into U.S. dollars, and dividends received. Our proportionate share of income or loss is included in non-operating income in our consolidated statements of income. As permitted under existing accounting guidance, we adopted a policy by which we recognize our share of UTI Asset Management Company Limited’s (UTI) earnings on a quarter lag as current financial information is not available in a timely manner. The basis difference between our carrying value and our proportionate share of UTI’s book value is primarily related to consideration paid in excess of the stepped-up basis of assets and liabilities on the date of purchase. Cost method investments consist of investments in entities for which we do not exercise significant influence over the operating and financial policies of the investee. We evaluate our equity and cost method investments for impairment when events or changes in circumstances indicate that the carrying value of the investment exceeds its fair value, and the decline in fair value is other than temporary. T. Rowe Price investment products held as trading include seed and discretionary investments in mutual funds and separately managed account products that are carried at fair value. These investments are valued in accordance with the valuation and pricing policy used to value our assets under management and as further described in the Revenue Recognition section below. Investments held by consolidated T. Rowe Price investment products are considered trading securities that are carried at fair value with corresponding changes in the investments’ fair values reflected in non-operating income in our consolidated statements of income. These investments are valued in accordance with the valuation and pricing policy used to value our assets under management and further described in the Revenue Recognition section below. CONCENTRATION OF RISK. Concentration of credit risk in accounts receivable is believed to be minimal in that our clients generally have substantial assets, including those in the investment portfolios that we manage for them. Our investments held as trading expose us to market risk, that is, the potential future loss of value that would result from a decline in the fair value of each investment or its underlying net assets. The underlying holdings of our assets under management are also subject to market risk, which may arise from changes in equity prices, credit ratings, foreign currency exchange rates, and interest rates. PROPERTY AND EQUIPMENT. Property and equipment is stated at cost net of accumulated depreciation and amortization computed using the straight-line method. Provisions for depreciation and amortization are based on the following weighted-average estimated useful lives: computer and communications software and equipment, 3 years; buildings and improvements, 32 years; leasehold improvements, 8 years; furniture and other equipment, 7 years; and leased land, 99 years. GOODWILL. We evaluate the carrying amount of goodwill in our consolidated balance sheets for possible impairment on an annual basis in the third quarter of each year using a fair value approach. Our evaluations have indicated that no impairment exists. We internally conduct, manage, and report our operations as one investment advisory business. We do not have distinct operating segments or components that separately constitute a business. Accordingly, we attribute goodwill to a single reportable business segment and reporting unit—our investment advisory business. REVENUE RECOGNITION. Fees for investment advisory services, which are based on a percentage of assets under management, and related administrative services that we provide to investment advisory clients, including the T. Rowe Price U.S. mutual funds and other investment products , are recognized in the period that our services are provided. Our assets under management are valued in accordance with a valuation and pricing policy that defines the valuation and pricing processes for each major type of investment held in T. Rowe Price U.S. mutual funds and other investment products . Fair values used in our processes are primarily determined from quoted market prices; prices furnished by dealers who make markets in such securities; or from data provided by an independent pricing service that considers yield or price of investments of comparable quality, coupon, maturity, and type. Investments for which market prices are not readily available are not a material portion of our total assets under management. Distribution and servicing fees earned from 12b-1 plans of the Advisor Class, R Class, and Variable Annuity II Class shares of certain T. Rowe Price U.S. mutual funds are recognized in the period that they are earned, which is the same period that the related products recognize their expense. These fees are offset entirely by the distribution and servicing costs paid to third-party financial intermediaries that source the assets of these share classes. We provide all services to the T. Rowe Price U.S. mutual funds under contracts that are subject to periodic review and approval by the funds’ Boards. Regulations require that the funds’ shareholders also approve material changes to investment advisory contracts. Taxes billed to our clients based on our fees for services rendered are not included in revenues. ADVERTISING. Costs of advertising are expensed the first time that the advertising takes place. STOCK-BASED COMPENSATION. We maintain three stockholder-approved employee long-term incentive plans (2012 Long-Term Incentive Plan, 2004 Stock Incentive Plan, and 2001 Stock Incentive Plan, collectively the LTI Plans) and two stockholder-approved non-employee director plans (2007 Non-Employee Director Equity Plan and 2017 Non-Employee Director Equity Plan, collectively the Director Plans). We believe that our stock-based compensation programs align the interests of our employees and directors with those of our common stockholders. As of December 31, 2017 , a total of 18,445,397 shares were available for future grant under the 2012 Long-Term Incentive Plan and the 2017 Non-Employee Director Equity Plan (2017 Plan). Under our LTI Plans, we have issued restricted shares and restricted stock units to employees that settle in shares of our common stock after vesting. Vesting of these awards is based on the individual continuing to render service over an average 5.0 year graded schedule. All restricted shareholders and restricted stock unitholders receive non-forfeitable cash dividends and cash dividend equivalents, respectively, on our dividend payable date. We are also authorized to grant qualified incentive and nonqualified fixed stock options with a maximum term of 10 years. We have not granted options to employees since 2015. We grant performance-based restricted stock units to certain executive officers in which the number of restricted stock units ultimately retained is determined based on achievement of certain performance thresholds. The number of restricted stock units retained is also subject to the same time-based vesting requirement as the other restricted stock units described above. Cash dividend equivalents are accrued and paid to the holders of performance-based restricted stock units only after the performance period has lapsed and the performance thresholds have been met. Under the Director Plans, we may grant options with a maximum term of 10 years, restricted shares, and restricted stock units to non-employee directors. Under the 2017 Plan, awards generally vest over one year and, in the case of restricted stock units, are settled upon the non-employee directors’ departure from the Board. For restricted shares, cash dividends are accrued and paid on only after the award vests. Restricted stock unit holders receive dividend equivalents in the form of unvested stock units that vest over the same period as the underlying award. We did not grant options to non-employee directors in 2017. We recognize the grant-date fair value of these awards as compensation expense ratably over the awards' requisite service period. Compensation expense recognized for performance-based restricted shares and units includes an estimate regarding the probability of the performance thresholds being met. Both time-based and performance-based units are valued on the grant-date using the closing market price of our common stock. The expense recognized prior to 2016 includes an estimate of awards that will be forfeited. Upon implementation of the new stock-based compensation accounting guidance in 2016, we elected to account for forfeitures as they occur. We used the following inputs to the Black-Scholes option-pricing model to estimate the fair value of each option granted in 2015 and 2016. Weighted-average 2015 2016 Grant-date fair value per option awarded $ 17.35 $ 10.62 Assumptions used: Expected life in years 7.0 6.8 Expected volatility 27 % 20 % Dividend yield 2.4 % 2.5 % Risk-free interest rate 1.9 % 1.6 % Our expected life assumptions are based on the vesting period for each option grant and our historical experience with respect to the average holding period from vesting to option exercise. The assumptions for expected volatility are based on historical experience for the same periods as our expected lives. Dividend yields are based on recent historical experience and future expectations. Risk-free interest rates are set using grant-date U.S. Treasury yield curves for the same periods as our expected lives. EARNINGS PER SHARE. We compute our basic and diluted earnings per share under the two-class method, which considers our outstanding restricted shares and stock units, on which we pay non-forfeitable dividends as if they were a separate class of stock. COMPREHENSIVE INCOME. The components of comprehensive income are presented in a separate statement following our consolidated statements of income and include net income, the change in net unrealized security holding gains (losses), and the change in our currency translation adjustments. The currency translation adjustments result from translating our proportionate share of the financial statements of UTI, our equity method investment, and certain consolidated T. Rowe Price investment products into U.S. dollars. Assets and liabilities are translated into U.S. dollars using year-end exchange rates, and revenues and expenses are translated using weighted-average exchange rates for the period. The changes in accumulated balances of each component of other comprehensive income, the deferred tax impacts of each component, and information about significant items reclassified out of accumulated other comprehensive income are presented in the notes to the financial statements. The notes also indicate the line item of our consolidated statements of income to which the significant reclassifications were recognized.

CASH EQUIVALENTS.

CASH EQUIVALENTS.	12 Months Ended
	Dec. 31, 2017
Cash and Cash Equivalents [Abstract]
CASH EQUIVALENTS	CASH EQUIVALENTS. Cash equivalent investments in the T. Rowe Price money market mutual funds aggregate $1,052.3 million at December 31, 2016 , and $1,726.4 million at December 31, 2017 . Dividends earned on these investments totaled $.2 million in 2015 , $.3 million in 2016 , and $9.1 million in 2017 .

INFORMATION ABOUT RECEIVABLES,

INFORMATION ABOUT RECEIVABLES, REVENUES, AND SERVICES.	12 Months Ended
	Dec. 31, 2017
Information about Receivables, Revenues, and Services [Abstract]
INFORMATION ABOUT RECEIVABLES, REVENUES, AND SERVICES	INFORMATION ABOUT RECEIVABLES, REVENUES, AND SERVICES. Accounts receivable from T. Rowe Price investment products , including the T. Rowe Price U.S. mutual funds , for advisory fees and advisory-related administrative services aggregate $303.1 million at December 31, 2016 , and $365.3 million at December 31, 2017 . Revenues from advisory services provided under agreements with the T. Rowe Price U.S. mutual funds and other investment products include: (in millions) 2015 2016 2017 T. Rowe Price U.S. mutual funds Stock and blended asset $ 2,241.9 $ 2,228.1 $ 2,570.9 Bond and money market 426.0 477.3 501.0 2,667.9 2,705.4 3,071.9 Other investment products Stock and blended asset 862.2 850.3 1,009.4 Bond, money market, and stable value 157.2 173.0 206.4 1,019.4 1,023.3 1,215.8 Total $ 3,687.3 $ 3,728.7 $ 4,287.7 Other investment products include advisory revenues of $367.8 million , $386.0 million , and $478.2 million for the year ended December 31, 2015 , 2016 , and 2017 , respectively, that were earned on other T. Rowe Price products . During 2015 and 2016 , we voluntarily waived $47.6 million and $10.5 million , respectively, in money market related fees, including advisory fees and fund expenses in order to maintain a positive yield for investors. Money market related fee waivers were immaterial in 2017 . The following table summarizes the assets under management on which we earned advisory fees. (in billions) Average during As of December 31, 2015 2016 2017 2016 2017 T. Rowe Price U.S. mutual funds Stock and blended asset $ 387.8 $ 386.1 $ 447.5 $ 401.3 $ 480.5 Bond and money market 105.8 109.4 121.0 112.9 125.8 493.6 495.5 568.5 514.2 606.3 Other investment products Stock and blended asset 210.3 211.1 256.4 220.8 291.9 Bond, money market, and stable value 64.0 71.6 84.1 75.8 92.9 274.3 282.7 340.5 296.6 384.8 Total $ 767.9 $ 778.2 $ 909.0 $ 810.8 $ 991.1 Investors that we serve are primarily domiciled in the U.S.; investment advisory clients outside the U.S. account for 4.7% and 5.8% of our assets under management at December 31, 2016 and 2017 , respectively. The following table summarizes the other fees we earned from the T. Rowe Price U.S. mutual funds . (in millions) 2015 2016 2017 Administrative fees $ 292.8 $ 277.3 $ 283.1 Distribution and servicing fees $ 151.5 $ 141.7 $ 147.0

INVESTMENTS.

INVESTMENTS.	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	INVESTMENTS. The carrying values of investments we do not consolidate at December 31 are as follows: (in millions) 2016 2017 T. Rowe Price investment products held as available-for-sale $ 709.0 $ 597.1 Equity method investments T. Rowe Price investment products 252.3 277.4 26% interest in UTI Asset Management Company Limited (India) 140.9 155.8 Investment partnerships 5.3 4.8 Trading investments T. Rowe Price investment products designated as an economic hedge of supplemental savings plan liability — 268.2 T. Rowe Price investment products 75.4 95.0 Cost method investments 73.6 78.0 U.S. Treasury note 1.0 1.0 Total $ 1,257.5 $ 1,477.3 At the end of the second quarter of 2017, we made the decision to economically hedge the market exposure associated with our supplemental savings plan liability with certain T. Rowe Price investment products . In order to fund the hedge portfolio, we used the proceeds from the sale of certain T. Rowe Price investment products held as available-for-sale as well as designated a T. Rowe Price U.S. mutual fund that was held as available-for-sale. During the last three years, certain T. Rowe Price investment products in which we provided initial seed capital at the time of formation were deconsolidated, as we no longer had a controlling interest. Depending on our ownership interest, we are now reporting our residual interests in these T. Rowe Price investment products as either equity method or available-for-sale investments. Additionally, during 2016 and 2017 , certain T. Rowe Price investment products that were being accounted for as equity method investments were consolidated, as we regained a controlling interest. The net impact of these changes on our consolidated balance sheets and income statements as of the dates the portfolios were deconsolidated or reconsolidated is detailed below. (in millions) 2015 2016 2017 Net increase (decrease) in assets of consolidated T. Rowe Price investment products $ (20.3 ) $ (1,342.8 ) $ (1,397.2 ) Net increase (decrease) in liabilities of consolidated T. Rowe Price investment products $ — $ (37.3 ) $ (153.1 ) Net increase (decrease) in redeemable non-controlling interests $ — $ (967.3 ) $ (1,042.6 ) Gains (losses) recognized upon deconsolidation $ (5.8 ) $ 2.2 $ .1 The losses and gains recognized upon deconsolidation were the result of reclassifying currency translation adjustments accumulated on certain T. Rowe Price investment products with non-USD functional currencies from accumulated other comprehensive income to non-operating income. T. ROWE PRICE INVESTMENT PRODUCTS - AVAILABLE-FOR-SALE These investments include: Aggregate cost Unrealized holding Aggregate fair value (in millions) gains losses December 31, 2016 Stock and blended asset funds $ 162.9 $ 88.0 $ (1.9 ) $ 249.0 Bond funds 463.3 1.7 (5.0 ) 460.0 Total $ 626.2 $ 89.7 $ (6.9 ) $ 709.0 December 31, 2017 Stock and blended asset funds $ 106.7 $ 14.1 $ — $ 120.8 Bond funds 480.5 .3 (4.5 ) 476.3 Total $ 587.2 $ 14.4 $ (4.5 ) $ 597.1 The following table details the number of holdings, the unrealized holding losses, and the aggregate fair value of T. Rowe Price investment products held as available-for-sale with unrealized losses categorized by the length of time they have been in a continuous unrealized loss position: (in millions) Number of holdings Unrealized holding losses Aggregate December 31, 2016 Less than 12 months 8 $ (4.2 ) $ 328.1 12 months or more 2 (2.7 ) 169.5 Total 10 $ (6.9 ) $ 497.6 December 31, 2017 Less than 12 months 2 $ (.4 ) $ 213.2 12 months or more 2 (4.1 ) 191.5 Total 4 $ (4.5 ) $ 404.7 In addition to the duration of the impairments, we reviewed the severity of the impairment as well as our intent and ability to hold the investments for a period of time sufficient for an anticipated recovery in fair value. Accordingly, impairment of these investment holdings was considered temporary at December 31, 2016 and 2017 . Dividends, excluding capital gain distributions, earned on these investments totaled $18.1 million in 2015 , $8.7 million in 2016 , and $8.2 million in 2017 . VARIABLE INTEREST ENTITIES. Our investments at December 31, 2016 and 2017 , include interests in variable interest entities that we do not consolidate as we are not deemed the primary beneficiary. Our maximum risk of loss related to our involvement with these entities is as follows: (in millions) 2016 2017 Investment carrying values $ 149.2 $ 129.2 Unfunded capital commitments 46.4 38.8 Uncollected investment advisory and administrative fees 5.9 7.7 $ 201.5 $ 175.7 The unfunded capital commitments totaling $46.4 million and $38.8 million at December 31, 2016 and 2017 , respectively, relate primarily to investment partnerships in which we have an existing investment. In addition to such amounts, a percentage of prior distributions may be called under certain circumstances.

FAIR VALUE MEASUREMENTS.

FAIR VALUE MEASUREMENTS.	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS. We determine the fair value of our cash equivalents and certain investments using the following broad levels of inputs as defined by related accounting standards: Level 1 – quoted prices in active markets for identical securities. Level 2 – observable inputs other than Level 1 quoted prices including, but not limited to, quoted prices for similar securities, interest rates, prepayment speeds, and credit risk. These inputs are based on market data obtained from independent sources. Level 3 – unobservable inputs reflecting our own assumptions based on the best information available. We do not value any investments using Level 3 inputs. These levels are not necessarily an indication of the risk or liquidity associated with our investments. There have been no transfers between the levels. The following table summarizes our investments that are recognized in our consolidated balance sheets using fair value measurements determined based on the differing levels of inputs. (in millions) Level 1 Level 2 December 31, 2016 Cash equivalents $ 1,052.3 $ — T. Rowe Price investment products held as available-for-sale 709.0 — T. Rowe Price investment products held as trading 60.3 15.1 Total $ 1,821.6 $ 15.1 December 31, 2017 Cash equivalents $ 1,726.4 $ — T. Rowe Price investment products held as available-for-sale 597.1 — T. Rowe Price investment products held as trading 345.8 17.4 Total $ 2,669.3 $ 17.4

CONSOLIDATED T. ROWE PRICE INVE

CONSOLIDATED T. ROWE PRICE INVESTMENT PRODUCTS.	12 Months Ended
	Dec. 31, 2017
Consolidated Sponsored Investment Portfolios [Abstract]
CONSOLIDATED T. ROWE PRICE INVESTMENT PRODUCTS	CONSOLIDATED T. ROWE PRICE INVESTMENT PRODUCTS . The T. Rowe Price investment products that we consolidate in our consolidated financial statements are generally those products we provided initial seed capital at the time of their formation and have a controlling interest. Our T. Rowe Price U.S. mutual funds are considered voting interest entities, while those regulated outside the U.S. are considered variable interest entities. The following table details the net assets of the consolidated T. Rowe Price investment products : December 31, 2016 December 31, 2017 (in millions) Voting Variable interest entities Total Voting interest entities Variable interest entities Total Cash and cash equivalents (1) $ 10.3 $ 55.3 $ 65.6 $ 7.1 $ 96.0 $ 103.1 Investments (2) 219.3 1,340.6 1,559.9 188.8 1,725.7 1,914.5 Other assets 4.8 50.2 55.0 12.9 17.9 30.8 Total assets 234.4 1,446.1 1,680.5 208.8 1,839.6 2,048.4 Liabilities 8.8 56.8 65.6 16.4 39.5 55.9 Net assets $ 225.6 $ 1,389.3 $ 1,614.9 $ 192.4 $ 1,800.1 $ 1,992.5 Attributable to T. Rowe Price Group $ 156.1 $ 771.6 $ 927.7 $ 131.6 $ 868.1 $ 999.7 Attributable to redeemable non-controlling interests 69.5 617.7 687.2 60.8 932.0 992.8 $ 225.6 $ 1,389.3 $ 1,614.9 $ 192.4 $ 1,800.1 $ 1,992.5 (1) Cash and cash equivalents includes $8.8 million and $6.2 million at December 31, 2016 and 2017 , respectively, of investments in T. Rowe Price money market mutual funds . (2) Investments include $4.2 million and $15.0 million at December 31, 2016 and 2017 , respectively, of T. Rowe Price investment products . Although we can redeem our net interest in these T. Rowe Price investment products at any time, we cannot directly access or sell the assets held by these products to obtain cash for general operations. Additionally, the assets of these investment products are not available to our general creditors. Since third-party investors in these investment products have no recourse to our credit, our overall risk related to the net assets of consolidated T. Rowe Price investment products is limited to valuation changes associated with our net interest. We, however, are required to recognize the valuation changes associated with all underlying investments held by these products in our consolidated statements of income and disclose the portion attributable to third-party investors as net income attributable to redeemable non-controlling interests. The operating results of the consolidated T. Rowe Price investment products , are reflected in our consolidated statements of income as follows: 2016 2017 (in millions) Voting Variable interest entities Total Voting Variable interest entities Total Operating expenses reflected in net operating income $ (1.6 ) $ (11.4 ) $ (13.0 ) $ (1.1 ) $ (11.2 ) $ (12.3 ) Net investment income reflected in non-operating income 22.5 98.6 121.1 18.8 175.1 193.9 Impact on income before taxes $ 20.9 $ 87.2 $ 108.1 $ 17.7 $ 163.9 $ 181.6 Net income attributable to T. Rowe Price Group $ 15.0 $ 54.1 $ 69.1 $ 13.3 $ 84.9 $ 98.2 Net income attributable to redeemable non-controlling interests 5.9 33.1 39.0 4.4 79.0 83.4 $ 20.9 $ 87.2 $ 108.1 $ 17.7 $ 163.9 $ 181.6 The operating expenses of these consolidated products are reflected in other operating expenses. In preparing our consolidated financial statements, we eliminated operating expenses of $6.5 million and $5.6 million in 2016 and 2017 , respectively, against the investment advisory and administrative fees earned from these products . The net investment income reflected in non-operating income includes dividend and interest income and realized and unrealized gains and losses on the underlying securities held by the consolidated T. Rowe Price investment products . The table below details the impact of these consolidated investment products on the individual lines of our consolidated statements of cash flows as follows: 2016 2017 (in millions) Voting Variable interest entities Total Voting Variable interest entities Total Net cash provided by (used in) operating activities $ (80.1 ) $ (1,086.5 ) $ (1,166.6 ) $ (33.0 ) $ (1,282.3 ) $ (1,315.3 ) Net cash provided by (used in) investing activities 21.6 19.8 41.4 (9.0 ) (55.2 ) (64.2 ) Net cash provided by (used in) financing activities 68.8 1,124.1 1,192.9 38.8 1,372.9 1,411.7 Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products — (2.1 ) (2.1 ) — 5.3 5.3 Net change in cash and cash equivalents during period 10.3 55.3 65.6 (3.2 ) 40.7 37.5 Cash and cash equivalents at beginning of year — — — 10.3 55.3 65.6 Cash and cash equivalents at end of year $ 10.3 $ 55.3 $ 65.6 $ 7.1 $ 96.0 $ 103.1 The net cash provided by financing activities during 2016 and 2017 , includes $277.9 million and $130.1 million , respectively, of net subscriptions we made into the consolidated T. Rowe Price investment products , net of dividends received. These cash flows were eliminated in consolidation. FAIR VALUE MEASUREMENTS. We determine the fair value of investments held by consolidated T. Rowe Price investment products using the following broad levels of inputs as defined by related accounting standards: Level 1 – quoted prices in active markets for identical securities. Level 2 – observable inputs other than Level 1 quoted prices including, but not limited to, quoted prices for similar securities, interest rates, prepayment speeds, and credit risk. These inputs are based on market data obtained from independent sources. Level 3 – unobservable inputs reflecting our own assumptions based on the best information available. The value of investments using Level 3 inputs is insignificant. These levels are not necessarily an indication of the risk or liquidity associated with these investment holdings. There have been no material transfers between the levels during 2016 and 2017. The following table summarizes the investment holdings held by our consolidated T. Rowe Price investment products using fair value measurements determined based on the differing levels of inputs. (in millions) Level 1 Level 2 December 31, 2016 Assets Cash equivalents $ 8.8 $ .8 Equity securities 281.8 325.3 Fixed income securities — 918.1 Other investments .4 34.3 $ 291.0 $ 1,278.5 Liabilities $ (.6 ) $ (13.6 ) December 31, 2017 Assets Cash equivalents $ 6.2 $ .7 Equity securities 536.0 667.5 Fixed income securities — 687.4 Other investments 1.3 22.3 $ 543.5 $ 1,377.9 Liabilities $ (.1 ) $ (13.7 )

PROPERTY AND EQUIPMENT.

PROPERTY AND EQUIPMENT.	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT	PROPERTY AND EQUIPMENT. Property and equipment at December 31 consists of: (in millions) 2016 2017 Computer and communications software and equipment $ 704.0 $ 824.4 Buildings and improvements 422.0 442.5 Leasehold improvements 108.2 121.0 Furniture and other equipment 158.3 168.9 Land 40.3 37.4 Leased land 2.7 2.7 1,435.5 1,596.9 Less accumulated depreciation and amortization 820.4 944.9 Total $ 615.1 $ 652.0 Compensation and related costs attributable to the development of computer software for internal use totaling $22.3 million in 2015 , $28.9 million in 2016 , and $62.3 million in 2017 have been capitalized. We occupy certain office facilities and lease computer and other equipment under noncancelable operating leases. Related rental expense was $31.1 million in 2015 , $32.8 million in 2016 , and $36.0 million in 2017 . Future minimum payments under these leases aggregate $37.8 million in 2018 , $37.2 million in 2019 , $32.9 million in 2020 , $29.6 million in 2021 , $24.6 million in 2022 , and $100.5 million in later years .

INCOME TAXES.

INCOME TAXES.	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES. The provision for income taxes consists of: (in millions) 2015 2016 2017 Current income taxes U.S. federal $ 669.5 $ 573.7 $ 708.1 State and local 134.3 105.8 131.0 Foreign 18.9 13.5 13.1 Deferred income taxes (tax benefits) (43.3 ) 13.5 71.7 Total $ 779.4 $ 706.5 $ 923.9 Our income tax provision for 2017 includes a non-recurring charge of $71.1 million to reflect the effect of the U.S. tax law changes enacted on December 22, 2017. The recognized charge is our reasonable estimate based on current interpretation of the tax law changes and includes $18.9 million for the remeasurement of our deferred tax assets and liabilities, and a $52.2 million U.S. federal and state tax charge for the mandatory deemed repatriation of foreign sourced net earnings. The federal tax portion will be payable over the next 8 years . We will continue to evaluate the impact of the tax law changes on our estimates and expectations due to changes in our interpretations of the law, assumptions used in applying the law, and additional guidance concerning the law that may be issued. We will report any applicable adjustments to these estimates in 2018 after our estimates are finalized. Deferred income taxes and benefits arise from temporary differences between taxable income for financial statement and income tax return purposes. The deferred income taxes (tax benefits) recognized as part of our provision for income taxes is related to: (in millions) 2015 2016 2017 Property and equipment $ (2.3 ) $ 3.2 $ (3.9 ) Stock-based compensation (14.6 ) 1.3 72.4 Accrued compensation (.9 ) (1.7 ) 1.2 Supplemental savings plan liability (27.4 ) (30.9 ) (8.3 ) Other-than-temporary impairments of available-for-sale investments (.4 ) 10.0 7.3 Unrealized holding gains recognized in non-operating income (2.4 ) 31.6 10.7 Other 4.7 — (7.7 ) Total deferred income taxes (tax benefits) $ (43.3 ) $ 13.5 $ 71.7 The following table reconciles the statutory federal income tax rate to our effective income tax rate. 2015 2016 2017 Statutory U.S. federal income tax rate 35.0 % 35.0 % 35.0 % Impact of U.S. tax reform — — 2.9 State income taxes for current year, net of federal income tax benefits (1) 4.3 3.8 3.9 Net income attributable to redeemable non-controlling interests — (.7 ) (1.3 ) Net excess tax benefits from stock-based compensation plans activity — (1.7 ) (3.0 ) Other items (.4 ) (.4 ) (.6 ) Effective income tax rate 38.9 % 36.0 % 36.9 % (1) In 2017, state income benefits totaling (.4)% are reflected in the total benefits for net income attributable to redeemable non-controlling interests and stock-based compensation plans activity. The amounts were not material in 2015 and 2016 . The net deferred tax assets recognized in our consolidated balance sheets in other assets as of December 31 relate to the following: (in millions) 2016 2017 Deferred tax liabilities Property and equipment $ (39.2 ) $ (35.3 ) Net unrealized holding gains recognized in income (43.2 ) (53.9 ) Net unrealized holding gains on investments held as available-for-sale (33.4 ) (3.1 ) Other (27.5 ) (18.9 ) (143.3 ) (111.2 ) Deferred tax assets Stock-based compensation 165.1 92.7 Asset impairments 16.1 8.8 Accrued compensation 5.6 4.4 Supplemental savings plan 58.3 66.6 Currency translation adjustment 23.0 2.2 Other 7.7 6.8 275.8 181.5 Net deferred tax asset $ 132.5 $ 70.3 We have not recognized a state deferred tax liability for unremitted earnings of our foreign subsidiaries as T. Rowe Price intends to indefinitely reinvest these earnings outside the U.S. The unremitted earnings of these subsidiaries are estimated to be approximately $604 million at December 31, 2017 . If these earnings were distributed to the U.S. in the form of dividends or otherwise, or if any of the entities were sold or otherwise transferred, we would be subject to state and local income taxes. Determination of the amount of the unrecognized deferred state liability related to these earnings is not practicable. Other assets include tax refund receivables of $8.1 million at December 31, 2016 , and $43.2 million at December 31, 2017 . Cash outflows from operating activities include net income taxes paid of $778.6 million in 2015 , $680.6 million in 2016 , and $857.7 million in 2017 . Additional income tax benefit arising from stock-based compensation plans activity totaling $23.2 million in 2015 , $31.6 million in 2016 , and $75.5 million in 2017 reduced the amount of income taxes that would have otherwise been payable. The income tax benefits for 2016 and 2017 were recognized in the income tax provision compared with additional paid in capital in 2015. The following table summarizes the changes in our unrecognized tax benefits. (in millions) 2015 2016 2017 Balance at beginning of year $ 5.6 $ 5.8 $ 6.2 Changes in tax positions related to Current year .7 .6 1.5 Prior years 1.8 — .1 Expired statute of limitations (2.3 ) (.2 ) (.2 ) Balance at end of year $ 5.8 $ 6.2 $ 7.6 If recognized, these tax benefits would affect our effective tax rate; however, we do not expect that unrecognized tax benefits for tax positions taken with respect to 2017 and prior years will significantly change in 2018 . The U.S. has concluded examinations related to federal tax obligations through the year 2015 . A net interest payable related to our unrecognized tax benefits of $1.2 million at December 31, 2016 , and $1.5 million at December 31, 2017 , are recognized in our consolidated balance sheets. Our accounting policy with respect to interest and penalties arising from income tax settlements is to recognize them as part of our provision for income taxes. Interest recognized as part of our provision for income taxes was not material.

STOCKHOLDERS' EQUITY.

STOCKHOLDERS' EQUITY.	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
STOCKHOLDERS’ EQUITY	STOCKHOLDERS' EQUITY. SHARE REPURCHASES. The Board of Directors has authorized the future repurchase of up to 15,183,779 common shares as of December 31, 2017 . DIVIDENDS. Regular cash dividends declared per share were $2.08 in 2015 , $2.16 in 2016 , and $2.28 in 2017 . A $2.00 per share special dividend was also declared and paid during 2015. RESTRICTED CAPITAL. Our consolidated stockholders' equity at December 31, 2017 , includes about $142 million that is restricted as to use by various regulations and agreements arising in the ordinary course of our business.

STOCK-BASED COMPENSATION.

STOCK-BASED COMPENSATION.	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION. SHARES AUTHORIZED FOR STOCK-BASED COMPENSATION PROGRAMS. At December 31, 2017 , a total of 39,301,717 shares of unissued common stock were authorized for issuance under our stock-based compensation plans. Additionally, a total of 2,693,679 shares are authorized for issuance under a plan whereby substantially all employees may acquire common stock through payroll deductions at prevailing market prices. STOCK OPTIONS. The following table summarizes the status of, and changes in, our stock options during 2017 . Options Weighted- average exercise price Weighted-average remaining contractual term in years Outstanding at December 31, 2016 24,364,322 $ 61.90 Exercised (8,977,164 ) $ 53.04 Forfeited (126,404 ) $ 75.16 Expired (39,631 ) $ 76.06 Outstanding at December 31, 2017 15,221,123 $ 66.98 5.1 Exercisable at December 31, 2017 11,140,190 $ 63.79 4.5 Compensation and related costs includes a charge for stock option-based compensation expense of $63.7 million in 2015 , $44.9 million in 2016 , and $28.1 million in 2017 . The total intrinsic value of options exercised was $108.1 million in 2015 , $150.5 million in 2016 , and $293.0 million in 2017 . At December 31, 2017 , the aggregate intrinsic value of in-the-money options outstanding was $577.6 million , including $458.3 million related to options exercisable. RESTRICTED SHARES AND STOCK UNITS. The following table summarizes the status of, and changes in, our nonvested restricted shares and restricted stock units during 2017 . Restricted shares Restricted stock units Weighted- average fair value Nonvested at December 31, 2016 931,508 4,634,461 $ 72.19 Time-based grants 17,022 2,026,176 $ 100.24 Performance-based grants — 114,454 $ 101.79 Vested (value at vest date was $164.5 million) (455,958 ) (1,111,857 ) $ 71.77 Forfeited (19,457 ) (106,323 ) $ 72.32 Nonvested at December 31, 2017 473,115 5,556,911 $ 82.37 Nonvested at December 31, 2017 , includes 7,200 performance-based restricted shares and 407,808 performance-based restricted stock units. These nonvested performance-based restricted shares and units include 7,200 shares and 293,354 units for which the performance period has lapsed and the performance threshold has been met. Compensation and related costs includes expenses for restricted shares and restricted stock units of $85.3 million in 2015 , $116.7 million in 2016 , and $124.0 million in 2017 . At December 31, 2017 , non-employee directors held 78,286 vested stock units that will convert to common shares upon their separation from the Board. FUTURE STOCK-BASED COMPENSATION EXPENSE. The following table presents the compensation expense (in millions) to be recognized over the remaining vesting periods of the stock-based awards outstanding at December 31, 2017 . Estimated future compensation expense will change to reflect future grants changes in the probability of performance thresholds being met, and adjustments for actual forfeitures. First quarter 2018 $ 47.3 Second quarter 2018 46.7 Third quarter 2018 46.0 Fourth quarter 2018 40.3 Total 2018 180.3 2019 through 2023 176.1 Total $ 356.4

EARNINGS PER SHARE CALCULATIONS

EARNINGS PER SHARE CALCULATIONS.	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
EARNINGS PER SHARE CALCULATIONS	EARNINGS PER SHARE CALCULATIONS. The following table presents the reconciliation of net income attributable to T. Rowe Price Group to net income allocated to our common stockholders and the weighted-average shares that are used in calculating the basic and diluted earnings per share on our common stock. Weighted-average common shares outstanding assuming dilution reflect the potential dilution, determined using the treasury stock method, that could occur if outstanding stock options were exercised and non-participating stock awards vested. (in millions) 2015 2016 2017 Net income attributable to T. Rowe Price Group $ 1,223.0 $ 1,215.0 $ 1,497.8 Less: net income allocated to outstanding restricted stock and stock unit holders 16.1 25.5 33.9 Net income allocated to common stockholders $ 1,206.9 $ 1,189.5 $ 1,463.9 Weighted-average common shares Outstanding 254.6 245.5 241.2 Outstanding assuming dilution 260.9 250.3 245.1 The following table shows the weighted-average outstanding stock options that are excluded from the calculation of diluted earnings per common share as the inclusion of such shares would be anti-dilutive. (in millions) 2015 2016 2017 Weighted-average outstanding stock options excluded 6.4 9.9 5.0

OTHER COMPREHENSIVE INCOME AND

OTHER COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME.	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
OTHER COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME	OTHER COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME. The following table presents the impact of the components of other comprehensive income or loss on deferred tax benefits (income taxes). (in millions) 2015 2016 2017 Net deferred tax benefits (income taxes) on: Net unrealized holding gains or losses $ 5.1 $ .6 $ (14.6 ) Reclassification adjustments recognized in the provision for income taxes: Capital gain distributions 7.9 2.4 1.4 Net gains realized on dispositions 20.7 20.9 32.5 Net gains recognized upon transfer to trading investments — — 9.2 Other-than-temporary impairments (1.9 ) — — Net deferred tax benefits (income taxes) on net unrealized holding gains or losses 31.8 23.9 28.5 Currency translation adjustments 3.8 3.5 (18.5 ) Reclassification adjustment recognized in the provision for income taxes upon deconsolidation of T. Rowe Price investment product (1.2 ) .8 — Total deferred tax benefits (income taxes) on currency translation adjustments 2.6 4.3 (18.5 ) Total net deferred tax benefits (income taxes) $ 34.4 $ 28.2 $ 10.0 The changes in each component of accumulated other comprehensive income (loss), including reclassification are presented below. Currency translation adjustments (in millions) Net unrealized holding gains Equity method investments Consolidated T. Rowe Price investment products - variable interest entities Total currency translation adjustments Total Balances at December 31, 2014 $ 165.5 $ (25.7 ) $ (3.4 ) $ (29.1 ) $ 136.4 Other comprehensive income (loss) before reclassifications and income taxes (4.5 ) (8.1 ) (4.9 ) (13.0 ) (17.5 ) Reclassification adjustments recognized in non-operating income (72.5 ) — 5.8 5.8 (66.7 ) (77.0 ) (8.1 ) .9 (7.2 ) (84.2 ) Net deferred tax benefits (income taxes) 31.8 2.9 (.3 ) 2.6 34.4 Other comprehensive income (loss) (45.2 ) (5.2 ) .6 (4.6 ) (49.8 ) Balances at December 31, 2015 120.3 (30.9 ) (2.8 ) (33.7 ) 86.6 Reclassification of accumulated other comprehensive income to retained earnings upon adoption of the new consolidation accounting guidance (32.0 ) (.5 ) — (.5 ) (32.5 ) Balance at January 1, 2016 88.3 (31.4 ) (2.8 ) (34.2 ) 54.1 Other comprehensive income (loss) before reclassifications and income taxes (7.0 ) (1.6 ) (7.0 ) (8.6 ) (15.6 ) Reclassification adjustments recognized in non-operating income (53.0 ) — (2.2 ) (2.2 ) (55.2 ) (60.0 ) (1.6 ) (9.2 ) (10.8 ) (70.8 ) Net deferred tax benefits (income taxes) 23.9 .7 3.6 4.3 28.2 Other comprehensive income (loss) (36.1 ) (.9 ) (5.6 ) (6.5 ) (42.6 ) Balances at December 31, 2016 52.2 (32.3 ) (8.4 ) (40.7 ) 11.5 Other comprehensive income (loss) before reclassifications and income taxes 37.4 2.6 45.2 47.8 85.2 Reclassification adjustments recognized in non-operating income (110.2 ) — (.1 ) (.1 ) (110.3 ) (72.8 ) 2.6 45.1 47.7 (25.1 ) Net deferred tax benefits (income taxes) 28.5 (.9 ) (17.6 ) (18.5 ) 10.0 Other comprehensive income (loss) (44.3 ) 1.7 27.5 29.2 (15.1 ) Balances at December 31, 2017 $ 7.9 $ (30.6 ) $ 19.1 $ (11.5 ) $ (3.6 )

DELL APPRAISAL RIGHTS MATTER.

DELL APPRAISAL RIGHTS MATTER.	12 Months Ended
	Dec. 31, 2017
Unusual or Infrequent Items, or Both [Abstract]
DELL APPRAISAL RIGHTS MATTER	DELL APPRAISAL RIGHTS MATTER. In 2016, we paid $166.2 million to compensate certain T. Rowe Price mutual funds, trusts, separately managed accounts, and subadvised clients (collectively, Clients) for the denial of their appraisal rights by the Delaware Chancery Court (Court) in connection with the 2013 leveraged buyout of Dell, Inc. (Dell). The Court ruled on May 11, 2016, that the Clients could not pursue an appraisal of any shares they held that were voted in favor of the Dell merger. The appraisal statute governing the transaction required the record holder to vote against or abstain from voting on the transaction in order to assert appraisal rights. After previously voting against prior transaction proposals, the voting instructions submitted on behalf of the Clients in connection with voting on the final proposed transaction were incorrectly submitted in favor of the transaction. On May 31, 2016, the Court determined that the fair value of Dell at the time of the merger was $17.62 per share, as opposed to the $13.75 price offered in the transaction. As a result, any shareholder perfecting appraisal rights is entitled to a payment at $17.62 per share plus statutory interest from the date the Dell transaction closed subject to possible appeal of the Court’s decision. The compensation to Clients was intended to make them whole for the voting discrepancy that resulted in the denial of their appraisal rights. On December 30, 2016, we entered into a settlement agreement for $100.0 million with our insurance carrier for insurance proceeds related to this matter. We recognized the proceeds as a reduction to the $166.2 million nonrecurring charge that we recognized earlier in 2016 and received the proceeds in January 2017. We received an additional $50 million in insurance proceeds from other insurance carriers in early 2017 and recognized a related reduction in operating expenses. In accordance with the compensation payment, the Clients agreed that in the event the findings made by the Court regarding the fair value of Dell or the amount of interest to be applied were modified by a final, non-appealable judgment, T. Rowe Price and the Clients would make an appropriate adjustment between themselves, calculated in a manner that is consistent with the methodology used to compensate Clients. In December 2016, several parties, including Dell and the successful appraisal petitioners, filed appeals to the Delaware Supreme Court to challenge the Court’s valuation ruling. On December 14, 2017, the Delaware Supreme Court reversed the Court's judgment and remanded the case for further proceedings. It is not clear how the Court will eventually rule and what the ultimate valuation will be, although the Supreme Court’s opinion suggests that the deal price of $13.75 may be the ultimate outcome. Once the Court enters a final, non-appealable judgment, Clients will be required to repay any overpayment using the methodology used to calculate the original payment. We estimate that the first $15.2 million reclaimed from our Clients would be paid back to T. Rowe Price Group. We would then be required to repay any additional reclaimed funds to our insurers in a specific order.

COMMITMENTS AND CONTINGENCIES.

COMMITMENTS AND CONTINGENCIES.	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES. On February 14, 2017, T. Rowe Price Group, Inc., T. Rowe Price Associates, Inc., T. Rowe Price Trust Company, current and former members of the management committee, and trustees of the T. Rowe Price U.S. Retirement Program were named as defendants in a lawsuit filed in the United States District Court for the District of Maryland. The lawsuit alleges breaches of ERISA’s fiduciary duty and prohibited transaction provisions on behalf of a class of all participants and beneficiaries of the T. Rowe Price 401(k) Plan from February 14, 2011, to the time of judgment. The plaintiffs are seeking certification of the complaint as a class action. T. Rowe Price believes the claims are without merit and is vigorously defending the action. This matter is in the early stages of litigation and we cannot predict the eventual outcome or whether it will have a material negative impact on our financial results, or estimate the possible loss or range of loss that may arise from any negative outcome. On April 27, 2016, certain shareholders in the T. Rowe Price Blue Chip Growth Fund, T. Rowe Price Capital Appreciation Fund, T. Rowe Price Equity Income Fund, T. Rowe Price Growth Stock Fund, T. Rowe Price International Stock Fund, T. Rowe Price High Yield Fund, T. Rowe Price New Income Fund and T. Rowe Price Small Cap Stock Fund (the “Funds”) filed a Section 36(b) complaint under the caption Zoidis v. T. Rowe Price Assoc., Inc., against T. Rowe Price Associates, Inc. (“T. Rowe Price”) in the United States District Court for the Northern District of California. The complaint alleges that the management fees for the identified funds are excessive because T. Rowe Price charges lower advisory fees to subadvised clients with funds in the same strategy. The complaint seeks to recover the allegedly excessive advisory fees received by T. Rowe Price in the year preceding the start of the lawsuit, along with investments’ returns and profits. In the alternative, the complaint seeks the rescission of each fund’s investment management agreement and restitution of any allegedly excessive management fees. T. Rowe Price believes the claims are without merit and is vigorously defending the action. This matter is in the early stages of litigation and we cannot predict the eventual outcome or whether it will have a material negative impact on our financial results, or estimate the possible loss or range of loss that may arise from any negative outcome. In addition to the matters discussed above, various claims against us arise in the ordinary course of business, including employment-related claims. In the opinion of management, after consultation with counsel, the likelihood of an adverse determination in one or more of these pending ordinary course of business claims that would have a material adverse effect on our financial position or results of operations is remote.

OTHER DISCLOSURES.

OTHER DISCLOSURES.	12 Months Ended
	Dec. 31, 2017
Other Disclosures [Abstract]
OTHER DISCLOSURES.	OTHER DISCLOSURES. RETIREMENT PLANS. Compensation and related costs includes expense recognized for our defined contribution retirement plans of $74.9 million in 2015 , $80.7 million in 2016 , and $89.4 million in 2017 . SUPPLEMENTAL SAVINGS PLAN. The Supplemental Savings Plan provides certain senior officers the opportunity to defer receipt of up to 100% of their cash incentive compensation earned for a respective calendar year during which services are provided. The amounts deferred are adjusted in accordance with the hypothetical investments chosen by the officer from a list of mutual funds. The officer can initially defer these amounts for a period of two to 15 years. For 2015 , 2016 and 2017 , senior officers elected to defer $72.8 million , $83.4 million , and $95.5 million , respectively.

SUPPLEMENTARY CONSOLIDATING CAS

SUPPLEMENTARY CONSOLIDATING CASH FLOW STATEMENT.	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
SUPPLEMENTARY CONSOLIDATING CASH FLOW STATEMENT	SUPPLEMENTARY CONSOLIDATING CASH FLOW STATEMENT. The following table summarizes the cash flows that are attributable to T. Rowe Price Group, our consolidated T. Rowe Price investment products , and the related eliminations required in preparing the statement. 2016 2017 (in millions) Cash flow attributable to T. Rowe Price Group Cash flow attributable to consolidated T. Rowe Price investment products Eliminations As reported Cash flow attributable to T. Rowe Price Group Cash flow attributable to consolidated T. Rowe Price investment products Eliminations As reported Cash flows from operating activities Net income $ 1,215.0 $ 108.1 $ (69.1 ) $ 1,254.0 $ 1,497.8 $ 181.6 $ (98.2 ) $ 1,581.2 Adjustments to reconcile net income to net cash provided by (used in) operating activities Depreciation and amortization of property and equipment 133.4 — — 133.4 143.6 — — 143.6 Stock-based compensation expense 161.6 — — 161.6 152.0 — — 152.0 Realized gains on dispositions of available-for-sale T. Rowe Price investment products (53.0 ) — — (53.0 ) (83.1 ) — — (83.1 ) Gains recognized upon transfer of an available-for-sale T. Rowe Price investment products to T. Rowe Price investment products held as trading — — — — (23.6 ) — — (23.6 ) Net gains recognized on investments (100.1 ) — 69.1 (31.0 ) (147.9 ) — 98.2 (49.7 ) Investments in T. Rowe Price mutual funds held as trading to economically hedge supplemental savings plan liability — — — — (218.6 ) — — (218.6 ) Net change in trading securities held by consolidated T. Rowe Price investment products — (1,297.9 ) — (1,297.9 ) — (1,492.9 ) — (1,492.9 ) Changes in accounts receivable and accrued revenue (9.3 ) — — (9.3 ) (100.8 ) — — (100.8 ) Changes in payables and accrued liabilities 101.5 37.1 — 138.6 169.1 154.3 — 323.4 Other changes in assets and liabilities (105.4 ) (13.9 ) (6.6 ) (125.9 ) 163.3 (158.3 ) (7.0 ) (2.0 ) Net cash provided by (used in) operating activities 1,343.7 (1,166.6 ) (6.6 ) 170.5 1,551.8 (1,315.3 ) (7.0 ) 229.5 Net cash provided by (used in) investing activities (219.7 ) 41.4 284.5 106.2 (33.9 ) (64.2 ) 137.1 39.0 Net cash used in financing activities attributable to T. Rowe Price Group (1,091.4 ) — — (1,091.4 ) (820.1 ) — — (820.1 ) Net subscriptions received from redeemable non-controlling interest holders — 1,192.9 (277.9 ) 915.0 — 1,411.7 (130.1 ) 1,281.6 Net cash provided by (used in) financing activities (1,091.4 ) 1,192.9 (277.9 ) (176.4 ) (820.1 ) 1,411.7 (130.1 ) 461.5 Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products — (2.1 ) — (2.1 ) — 5.3 — 5.3 Net change in cash and cash equivalents during period 32.6 65.6 — 98.2 697.8 37.5 — 735.3 Cash and cash equivalents at beginning of year 1,172.3 — — 1,172.3 1,204.9 65.6 — 1,270.5 Cash and cash equivalents at end of period $ 1,204.9 $ 65.6 $ — $ 1,270.5 $ 1,902.7 $ 103.1 $ — $ 2,005.8

SUPPLEMENTARY QUARTERLY FINANCI

SUPPLEMENTARY QUARTERLY FINANCIAL DATA (Unaudited).	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
SUPPLEMENTARY QUARTERLY FINANCIAL DATA (Unaudited)	SUPPLEMENTARY QUARTERLY FINANCIAL DATA (Unaudited). Net revenues Net income (2) Net income attributable to T. Rowe Price Group (2) Basic earnings on common stock (1) Diluted earnings on common stock (1),(2) (in millions) (per share) 2016 1st quarter $ 994.1 $ 313.3 $ 304.1 $ 1.21 $ 1.18 2nd quarter $ 1,044.7 $ 211.2 $ 203.3 $ .81 $ .79 3rd quarter $ 1,092.9 $ 362.7 $ 327.8 $ 1.30 $ 1.28 4th quarter $ 1,091.2 $ 366.8 $ 379.8 $ 1.53 $ 1.50 2017 1st quarter $ 1,113.6 $ 400.4 $ 385.9 $ 1.56 $ 1.54 2nd quarter $ 1,171.6 $ 390.0 $ 373.9 $ 1.52 $ 1.50 3rd quarter $ 1,221.7 $ 404.2 $ 390.9 $ 1.59 $ 1.56 4th quarter $ 1,286.1 $ 386.6 $ 347.1 $ 1.40 $ 1.37 (1) The sums of quarterly earnings per share may not equal annual earnings per share because the computations are done independently. (2) The second quarter of 2016 includes a nonrecurring operating charge of $166.2 million , or $.39 in diluted earnings per share, related to our decision to compensate certain clients in regard to the Dell appraisal rights matter. In the fourth quarter of 2016, we recognized an offset to this charge for a related insurance recovery of $100 million , or $.24 in diluted earnings per share. During the first quarter of 2017, we recognized an additional $50 million in insurance recoveries, or $.12 in diluted earnings per share relating to the Dell matter. For more details related to the Dell appraisal rights matter, see Note 12 to the consolidated financial statements. During the fourth quarter of 2017, we recognized a nonrecurring charge of $71.1 million related to the U.S. tax law changes that were enacted on December 22, 2017. See Note 7 to the consolidated financial statements for further details.

SUMMARY OF SIGNIFICANT ACCOUN26

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES. (Policies)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of preparation - basis of accounting	These consolidated financial statements have been prepared by our management in accordance with accounting principles generally accepted in the United States.
Basis of preparation - use of estimates	These principles require that we make certain estimates and assumptions. Actual results may vary from our estimates.
Newly issued but not yet adopted accounting guidance	In May 2014, the FASB issued Accounting Standards Update No. 2014-09 — Revenue from Contracts with Customers, and subsequently has issued several related accounting standard updates clarifying several aspects of ASU 2014-09, including technical corrections and improvements (ASC 606). The standard update provides a single, comprehensive revenue recognition model for all contracts with customers to improve comparability within industries, across industries, and across capital markets. It contains principles to apply to determine the measurement of revenue and the timing of when it is recognized. We will adopt the new standard on its effective date, January 1, 2018, using the retrospective approach with adjustments to each prior period. We concluded that the new standards do not materially change the timing of revenue recognition. However, the presentation of certain revenue related expenses totaling about $60 million in 2016 and 2017 will change from being recognized net against the related revenues to being reported within operating expenses. Additionally, we plan to enhance disclosures in accordance with the standard's disclosure requirements in 2018. In January 2016, the FASB issued Accounting Standards Update No. 2016-01 — Financial Instruments — Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. This standard update addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments and requires a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. We will adopt the new standard on its effective date, January 1, 2018. Upon adoption, we will reclassify net unrealized holding gains recognized on investments in T. Rowe Price products totaling $7.9 million from accumulated other comprehensive income to retained earnings. After January 1, 2018, the change in the fair value of investments in T. Rowe Price investment product s previously accounted for as available-for-sale investments will be recognized in our consolidated income statement rather than our consolidated statement of comprehensive income. The impact upon implementation of the standard on our investments without a readily determinable fair value is not material. In February 2016, the FASB issued Accounting Standards Update No. 2016-02 — Leases (Topic 842). The standard update seeks to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The standards update is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. We are currently evaluating the impact this standard will have on our financial position and results of operations. We have considered all other newly issued accounting guidance that is applicable to our operations and the preparation of our consolidated financial statements, including guidance which we have not yet adopted. We do not believe that any such guidance will have a material effect on our financial position or results of operation.
Consolidation	Our consolidated financial statements include the accounts of all subsidiaries and T. Rowe Price investment products in which we have a controlling interest. We are generally deemed to have a controlling interest when we own the majority of a voting interest entity (VOE) or are deemed to be the primary beneficiary of a variable interest entity (VIE). We perform an analysis of our investments to determine if the investment entity is a VOE or VIE. Our analysis involves judgment and considers several factors, including an entity’s legal organization, capital structure, the rights of the equity investment holders, our ownership interest in the entity, and our contractual involvement with the entity. We continually review and reconsider our VOE or VIE conclusions upon the occurrence of certain events, such as changes to our ownership interest, changes to an entity’s legal structure, or amendments to governing documents. Upon consolidation of T. Rowe Price investment products , we retain the specialized investment company accounting principles of the underlying funds. All material accounts and transactions between consolidated entities are eliminated in consolidation. Variable interest entities VIEs are entities that, by design: (i ) lack sufficient equity to permit the entity to finance its activities independently or (ii) have equity holders that do not have the power to direct the activities of the entity that most significantly impact the entity’s economic performance, the obligation to absorb the entity’s losses, or the rights to receive the entity’s residual returns. We consolidate a VIE when we are the primary beneficiary, which is the party that has both (i) the power to direct the activities of the VIE that most significantly impact its economic performance and (ii) the obligation to absorb losses of the entity or the right to receive benefits from the VIE that could potentially be significant. Our Luxembourg-based SICAV funds and other T. Rowe Price investment products regulated outside the U.S. were determined to be VIEs. Along with VIEs that we consolidate, we also hold variable interests in other VIEs, including several investment partnerships that are not consolidated because we are not the primary beneficiary. Redeemable non-controlling interests We recognize redeemable non-controlling interests for the portion of the net assets of our consolidated T. Rowe Price investment products held by unrelated third-party investors as their interest is convertible to cash and other assets at their option. As such, we reflect redeemable non-controlling interests as temporary equity in our consolidated balance sheets. Investments in T. Rowe Price money market mutual funds We do not consider our investments in T. Rowe Price money market mutual funds when performing our consolidation analysis as the guidance provides a scope exception for interests in entities that are required to comply with, or operate in accordance with, requirements similar to those in Rule 2a-7 of the Investment Company Act of 1940 for registered money market funds.
Cash equivalents	Cash equivalents consist primarily of short-term, highly liquid investments in T. Rowe Price money market mutual funds . The cost of these funds is equivalent to fair value.
Available-for-sale sponsored investment portfolios	T. Rowe Price investment products that are accounted for as available-for-sale investments have been made for both general corporate investment purposes and to provide seed capital for newly formed product s. These investments are carried at fair value using the quoted closing net asset value (NAV) per share of each fund as of the balance sheet date. Changes in net unrealized holding gains or losses on these investments are recognized in other comprehensive income. We review the carrying amount of each investment on a quarterly basis and recognize an impairment charge in non-operating investment income whenever an unrealized loss is considered other than temporary. In determining whether a holding is other-than-temporarily impaired, we consider various factors, including the duration of time it has existed, the severity of the impairment, any subsequent changes in value, and our intent and ability to hold the investment for a period of time sufficient for an anticipated recovery in fair value. Subject to the other considerations noted above, we believe a holding with an unrealized loss that has persisted daily throughout the six months between quarter-ends is generally presumed to have an other-than-temporary impairment. We may also recognize an other-than-temporary impairment if particular circumstances of the underlying investment do not warrant our belief that a near-term recovery is possible.
Equity and cost method investments	Equity method investments consist of investments in entities, including T. Rowe Price investment products , for which we have the ability to exercise significant influence over the operating and financial policies of the investee. The carrying values of these investments are adjusted to reflect our proportionate share of the investee's net income or loss, any unrealized gain or loss resulting from the translation of foreign-denominated financial statements into U.S. dollars, and dividends received. Our proportionate share of income or loss is included in non-operating income in our consolidated statements of income. As permitted under existing accounting guidance, we adopted a policy by which we recognize our share of UTI Asset Management Company Limited’s (UTI) earnings on a quarter lag as current financial information is not available in a timely manner. The basis difference between our carrying value and our proportionate share of UTI’s book value is primarily related to consideration paid in excess of the stepped-up basis of assets and liabilities on the date of purchase. Cost method investments consist of investments in entities for which we do not exercise significant influence over the operating and financial policies of the investee. We evaluate our equity and cost method investments for impairment when events or changes in circumstances indicate that the carrying value of the investment exceeds its fair value, and the decline in fair value is other than temporary.
Investments held as trading	T. Rowe Price investment products held as trading include seed and discretionary investments in mutual funds and separately managed account products that are carried at fair value. These investments are valued in accordance with the valuation and pricing policy used to value our assets under management and as further described in the Revenue Recognition section below. Investments held by consolidated T. Rowe Price investment products are considered trading securities that are carried at fair value with corresponding changes in the investments’ fair values reflected in non-operating income in our consolidated statements of income. These investments are valued in accordance with the valuation and pricing policy used to value our assets under management and further described in the Revenue Recognition section below.
Property and equipment	Property and equipment is stated at cost net of accumulated depreciation and amortization computed using the straight-line method. Provisions for depreciation and amortization are based on the following weighted-average estimated useful lives: computer and communications software and equipment, 3 years; buildings and improvements, 32 years; leasehold improvements, 8 years; furniture and other equipment, 7 years; and leased land, 99 years.
Goodwill	We evaluate the carrying amount of goodwill in our consolidated balance sheets for possible impairment on an annual basis in the third quarter of each year using a fair value approach. Our evaluations have indicated that no impairment exists. We internally conduct, manage, and report our operations as one investment advisory business. We do not have distinct operating segments or components that separately constitute a business. Accordingly, we attribute goodwill to a single reportable business segment and reporting unit—our investment advisory business.
Revenue recognition	Fees for investment advisory services, which are based on a percentage of assets under management, and related administrative services that we provide to investment advisory clients, including the T. Rowe Price U.S. mutual funds and other investment products , are recognized in the period that our services are provided. Our assets under management are valued in accordance with a valuation and pricing policy that defines the valuation and pricing processes for each major type of investment held in T. Rowe Price U.S. mutual funds and other investment products . Fair values used in our processes are primarily determined from quoted market prices; prices furnished by dealers who make markets in such securities; or from data provided by an independent pricing service that considers yield or price of investments of comparable quality, coupon, maturity, and type. Investments for which market prices are not readily available are not a material portion of our total assets under management. Distribution and servicing fees earned from 12b-1 plans of the Advisor Class, R Class, and Variable Annuity II Class shares of certain T. Rowe Price U.S. mutual funds are recognized in the period that they are earned, which is the same period that the related products recognize their expense. These fees are offset entirely by the distribution and servicing costs paid to third-party financial intermediaries that source the assets of these share classes. We provide all services to the T. Rowe Price U.S. mutual funds under contracts that are subject to periodic review and approval by the funds’ Boards. Regulations require that the funds’ shareholders also approve material changes to investment advisory contracts. Taxes billed to our clients based on our fees for services rendered are not included in revenues.
Advertising	Costs of advertising are expensed the first time that the advertising takes place.
Stock-based compensation	We maintain three stockholder-approved employee long-term incentive plans (2012 Long-Term Incentive Plan, 2004 Stock Incentive Plan, and 2001 Stock Incentive Plan, collectively the LTI Plans) and two stockholder-approved non-employee director plans (2007 Non-Employee Director Equity Plan and 2017 Non-Employee Director Equity Plan, collectively the Director Plans). We believe that our stock-based compensation programs align the interests of our employees and directors with those of our common stockholders. As of December 31, 2017 , a total of 18,445,397 shares were available for future grant under the 2012 Long-Term Incentive Plan and the 2017 Non-Employee Director Equity Plan (2017 Plan). Under our LTI Plans, we have issued restricted shares and restricted stock units to employees that settle in shares of our common stock after vesting. Vesting of these awards is based on the individual continuing to render service over an average 5.0 year graded schedule. All restricted shareholders and restricted stock unitholders receive non-forfeitable cash dividends and cash dividend equivalents, respectively, on our dividend payable date. We are also authorized to grant qualified incentive and nonqualified fixed stock options with a maximum term of 10 years. We have not granted options to employees since 2015. We grant performance-based restricted stock units to certain executive officers in which the number of restricted stock units ultimately retained is determined based on achievement of certain performance thresholds. The number of restricted stock units retained is also subject to the same time-based vesting requirement as the other restricted stock units described above. Cash dividend equivalents are accrued and paid to the holders of performance-based restricted stock units only after the performance period has lapsed and the performance thresholds have been met. Under the Director Plans, we may grant options with a maximum term of 10 years, restricted shares, and restricted stock units to non-employee directors. Under the 2017 Plan, awards generally vest over one year and, in the case of restricted stock units, are settled upon the non-employee directors’ departure from the Board. For restricted shares, cash dividends are accrued and paid on only after the award vests. Restricted stock unit holders receive dividend equivalents in the form of unvested stock units that vest over the same period as the underlying award. We did not grant options to non-employee directors in 2017. We recognize the grant-date fair value of these awards as compensation expense ratably over the awards' requisite service period. Compensation expense recognized for performance-based restricted shares and units includes an estimate regarding the probability of the performance thresholds being met. Both time-based and performance-based units are valued on the grant-date using the closing market price of our common stock. The expense recognized prior to 2016 includes an estimate of awards that will be forfeited. Upon implementation of the new stock-based compensation accounting guidance in 2016, we elected to account for forfeitures as they occur. We used the following inputs to the Black-Scholes option-pricing model to estimate the fair value of each option granted in 2015 and 2016. Weighted-average 2015 2016 Grant-date fair value per option awarded $ 17.35 $ 10.62 Assumptions used: Expected life in years 7.0 6.8 Expected volatility 27 % 20 % Dividend yield 2.4 % 2.5 % Risk-free interest rate 1.9 % 1.6 % Our expected life assumptions are based on the vesting period for each option grant and our historical experience with respect to the average holding period from vesting to option exercise. The assumptions for expected volatility are based on historical experience for the same periods as our expected lives. Dividend yields are based on recent historical experience and future expectations. Risk-free interest rates are set using grant-date U.S. Treasury yield curves for the same periods as our expected lives.
Earnings per share	We compute our basic and diluted earnings per share under the two-class method, which considers our outstanding restricted shares and stock units, on which we pay non-forfeitable dividends as if they were a separate class of stock.
Comprehensive income	The components of comprehensive income are presented in a separate statement following our consolidated statements of income and include net income, the change in net unrealized security holding gains (losses), and the change in our currency translation adjustments. The currency translation adjustments result from translating our proportionate share of the financial statements of UTI, our equity method investment, and certain consolidated T. Rowe Price investment products into U.S. dollars. Assets and liabilities are translated into U.S. dollars using year-end exchange rates, and revenues and expenses are translated using weighted-average exchange rates for the period. The changes in accumulated balances of each component of other comprehensive income, the deferred tax impacts of each component, and information about significant items reclassified out of accumulated other comprehensive income are presented in the notes to the financial statements. The notes also indicate the line item of our consolidated statements of income to which the significant reclassifications were recognized.

SUMMARY OF SIGNIFICANT ACCOUN27

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES. (Tables)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Assumptions used in option pricing model and grant date fair value of options	We used the following inputs to the Black-Scholes option-pricing model to estimate the fair value of each option granted in 2015 and 2016. Weighted-average 2015 2016 Grant-date fair value per option awarded $ 17.35 $ 10.62 Assumptions used: Expected life in years 7.0 6.8 Expected volatility 27 % 20 % Dividend yield 2.4 % 2.5 % Risk-free interest rate 1.9 % 1.6 %

INFORMATION ABOUT RECEIVABLES28

INFORMATION ABOUT RECEIVABLES, REVENUES, AND SERVICES. (Tables)	12 Months Ended
	Dec. 31, 2017
Information about Receivables, Revenues, and Services [Abstract]
Components of revenues from advisory services	Revenues from advisory services provided under agreements with the T. Rowe Price U.S. mutual funds and other investment products include: (in millions) 2015 2016 2017 T. Rowe Price U.S. mutual funds Stock and blended asset $ 2,241.9 $ 2,228.1 $ 2,570.9 Bond and money market 426.0 477.3 501.0 2,667.9 2,705.4 3,071.9 Other investment products Stock and blended asset 862.2 850.3 1,009.4 Bond, money market, and stable value 157.2 173.0 206.4 1,019.4 1,023.3 1,215.8 Total $ 3,687.3 $ 3,728.7 $ 4,287.7
Components of assets under management	The following table summarizes the assets under management on which we earned advisory fees. (in billions) Average during As of December 31, 2015 2016 2017 2016 2017 T. Rowe Price U.S. mutual funds Stock and blended asset $ 387.8 $ 386.1 $ 447.5 $ 401.3 $ 480.5 Bond and money market 105.8 109.4 121.0 112.9 125.8 493.6 495.5 568.5 514.2 606.3 Other investment products Stock and blended asset 210.3 211.1 256.4 220.8 291.9 Bond, money market, and stable value 64.0 71.6 84.1 75.8 92.9 274.3 282.7 340.5 296.6 384.8 Total $ 767.9 $ 778.2 $ 909.0 $ 810.8 $ 991.1
Components of other fees	The following table summarizes the other fees we earned from the T. Rowe Price U.S. mutual funds . (in millions) 2015 2016 2017 Administrative fees $ 292.8 $ 277.3 $ 283.1 Distribution and servicing fees $ 151.5 $ 141.7 $ 147.0

INVESTMENTS. (Tables)

INVESTMENTS. (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Unconsolidated investments	The carrying values of investments we do not consolidate at December 31 are as follows: (in millions) 2016 2017 T. Rowe Price investment products held as available-for-sale $ 709.0 $ 597.1 Equity method investments T. Rowe Price investment products 252.3 277.4 26% interest in UTI Asset Management Company Limited (India) 140.9 155.8 Investment partnerships 5.3 4.8 Trading investments T. Rowe Price investment products designated as an economic hedge of supplemental savings plan liability — 268.2 T. Rowe Price investment products 75.4 95.0 Cost method investments 73.6 78.0 U.S. Treasury note 1.0 1.0 Total $ 1,257.5 $ 1,477.3
Net impact of deconsolidation and consolidation on condensed consolidated balance sheets and income statements	The net impact of these changes on our consolidated balance sheets and income statements as of the dates the portfolios were deconsolidated or reconsolidated is detailed below. (in millions) 2015 2016 2017 Net increase (decrease) in assets of consolidated T. Rowe Price investment products $ (20.3 ) $ (1,342.8 ) $ (1,397.2 ) Net increase (decrease) in liabilities of consolidated T. Rowe Price investment products $ — $ (37.3 ) $ (153.1 ) Net increase (decrease) in redeemable non-controlling interests $ — $ (967.3 ) $ (1,042.6 ) Gains (losses) recognized upon deconsolidation $ (5.8 ) $ 2.2 $ .1
Available-for-sale T. Rowe Price investment products	These investments include: Aggregate cost Unrealized holding Aggregate fair value (in millions) gains losses December 31, 2016 Stock and blended asset funds $ 162.9 $ 88.0 $ (1.9 ) $ 249.0 Bond funds 463.3 1.7 (5.0 ) 460.0 Total $ 626.2 $ 89.7 $ (6.9 ) $ 709.0 December 31, 2017 Stock and blended asset funds $ 106.7 $ 14.1 $ — $ 120.8 Bond funds 480.5 .3 (4.5 ) 476.3 Total $ 587.2 $ 14.4 $ (4.5 ) $ 597.1
Continuous unrealized loss positions	The following table details the number of holdings, the unrealized holding losses, and the aggregate fair value of T. Rowe Price investment products held as available-for-sale with unrealized losses categorized by the length of time they have been in a continuous unrealized loss position: (in millions) Number of holdings Unrealized holding losses Aggregate December 31, 2016 Less than 12 months 8 $ (4.2 ) $ 328.1 12 months or more 2 (2.7 ) 169.5 Total 10 $ (6.9 ) $ 497.6 December 31, 2017 Less than 12 months 2 $ (.4 ) $ 213.2 12 months or more 2 (4.1 ) 191.5 Total 4 $ (4.5 ) $ 404.7
Maximum risk of loss related to investments in variable interest entities	Our maximum risk of loss related to our involvement with these entities is as follows: (in millions) 2016 2017 Investment carrying values $ 149.2 $ 129.2 Unfunded capital commitments 46.4 38.8 Uncollected investment advisory and administrative fees 5.9 7.7 $ 201.5 $ 175.7

FAIR VALUE MEASUREMENTS. (Table

FAIR VALUE MEASUREMENTS. (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair value measurements summary	The following table summarizes our investments that are recognized in our consolidated balance sheets using fair value measurements determined based on the differing levels of inputs. (in millions) Level 1 Level 2 December 31, 2016 Cash equivalents $ 1,052.3 $ — T. Rowe Price investment products held as available-for-sale 709.0 — T. Rowe Price investment products held as trading 60.3 15.1 Total $ 1,821.6 $ 15.1 December 31, 2017 Cash equivalents $ 1,726.4 $ — T. Rowe Price investment products held as available-for-sale 597.1 — T. Rowe Price investment products held as trading 345.8 17.4 Total $ 2,669.3 $ 17.4

CONSOLIDATED T. ROWE PRICE IN31

CONSOLIDATED T. ROWE PRICE INVESTMENT PRODUCTS. (Tables)	12 Months Ended
	Dec. 31, 2017
Consolidated Sponsored Investment Portfolios [Abstract]
Net assets of consolidated T. Rowe Price investment portfolios	The following table details the net assets of the consolidated T. Rowe Price investment products : December 31, 2016 December 31, 2017 (in millions) Voting Variable interest entities Total Voting interest entities Variable interest entities Total Cash and cash equivalents (1) $ 10.3 $ 55.3 $ 65.6 $ 7.1 $ 96.0 $ 103.1 Investments (2) 219.3 1,340.6 1,559.9 188.8 1,725.7 1,914.5 Other assets 4.8 50.2 55.0 12.9 17.9 30.8 Total assets 234.4 1,446.1 1,680.5 208.8 1,839.6 2,048.4 Liabilities 8.8 56.8 65.6 16.4 39.5 55.9 Net assets $ 225.6 $ 1,389.3 $ 1,614.9 $ 192.4 $ 1,800.1 $ 1,992.5 Attributable to T. Rowe Price Group $ 156.1 $ 771.6 $ 927.7 $ 131.6 $ 868.1 $ 999.7 Attributable to redeemable non-controlling interests 69.5 617.7 687.2 60.8 932.0 992.8 $ 225.6 $ 1,389.3 $ 1,614.9 $ 192.4 $ 1,800.1 $ 1,992.5 (1) Cash and cash equivalents includes $8.8 million and $6.2 million at December 31, 2016 and 2017 , respectively, of investments in T. Rowe Price money market mutual funds . (2) Investments include $4.2 million and $15.0 million at December 31, 2016 and 2017 , respectively, of T. Rowe Price investment products .
Operating results of consolidated T. Rowe Price investment portfolios	The operating results of the consolidated T. Rowe Price investment products , are reflected in our consolidated statements of income as follows: 2016 2017 (in millions) Voting Variable interest entities Total Voting Variable interest entities Total Operating expenses reflected in net operating income $ (1.6 ) $ (11.4 ) $ (13.0 ) $ (1.1 ) $ (11.2 ) $ (12.3 ) Net investment income reflected in non-operating income 22.5 98.6 121.1 18.8 175.1 193.9 Impact on income before taxes $ 20.9 $ 87.2 $ 108.1 $ 17.7 $ 163.9 $ 181.6 Net income attributable to T. Rowe Price Group $ 15.0 $ 54.1 $ 69.1 $ 13.3 $ 84.9 $ 98.2 Net income attributable to redeemable non-controlling interests 5.9 33.1 39.0 4.4 79.0 83.4 $ 20.9 $ 87.2 $ 108.1 $ 17.7 $ 163.9 $ 181.6
Cash flows of consolidated T. Rowe Price investment portfolios	The table below details the impact of these consolidated investment products on the individual lines of our consolidated statements of cash flows as follows: 2016 2017 (in millions) Voting Variable interest entities Total Voting Variable interest entities Total Net cash provided by (used in) operating activities $ (80.1 ) $ (1,086.5 ) $ (1,166.6 ) $ (33.0 ) $ (1,282.3 ) $ (1,315.3 ) Net cash provided by (used in) investing activities 21.6 19.8 41.4 (9.0 ) (55.2 ) (64.2 ) Net cash provided by (used in) financing activities 68.8 1,124.1 1,192.9 38.8 1,372.9 1,411.7 Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products — (2.1 ) (2.1 ) — 5.3 5.3 Net change in cash and cash equivalents during period 10.3 55.3 65.6 (3.2 ) 40.7 37.5 Cash and cash equivalents at beginning of year — — — 10.3 55.3 65.6 Cash and cash equivalents at end of year $ 10.3 $ 55.3 $ 65.6 $ 7.1 $ 96.0 $ 103.1
Fair values of investments held by consolidated T. Rowe Price investment portfolios	The following table summarizes the investment holdings held by our consolidated T. Rowe Price investment products using fair value measurements determined based on the differing levels of inputs. (in millions) Level 1 Level 2 December 31, 2016 Assets Cash equivalents $ 8.8 $ .8 Equity securities 281.8 325.3 Fixed income securities — 918.1 Other investments .4 34.3 $ 291.0 $ 1,278.5 Liabilities $ (.6 ) $ (13.6 ) December 31, 2017 Assets Cash equivalents $ 6.2 $ .7 Equity securities 536.0 667.5 Fixed income securities — 687.4 Other investments 1.3 22.3 $ 543.5 $ 1,377.9 Liabilities $ (.1 ) $ (13.7 )

PROPERTY AND EQUIPMENT. (Tables

PROPERTY AND EQUIPMENT. (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property and equipment summary	Property and equipment at December 31 consists of: (in millions) 2016 2017 Computer and communications software and equipment $ 704.0 $ 824.4 Buildings and improvements 422.0 442.5 Leasehold improvements 108.2 121.0 Furniture and other equipment 158.3 168.9 Land 40.3 37.4 Leased land 2.7 2.7 1,435.5 1,596.9 Less accumulated depreciation and amortization 820.4 944.9 Total $ 615.1 $ 652.0

INCOME TAXES. (Tables)

INCOME TAXES. (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedules of provision for income taxes and deferred income taxes (tax benefits)	The deferred income taxes (tax benefits) recognized as part of our provision for income taxes is related to: (in millions) 2015 2016 2017 Property and equipment $ (2.3 ) $ 3.2 $ (3.9 ) Stock-based compensation (14.6 ) 1.3 72.4 Accrued compensation (.9 ) (1.7 ) 1.2 Supplemental savings plan liability (27.4 ) (30.9 ) (8.3 ) Other-than-temporary impairments of available-for-sale investments (.4 ) 10.0 7.3 Unrealized holding gains recognized in non-operating income (2.4 ) 31.6 10.7 Other 4.7 — (7.7 ) Total deferred income taxes (tax benefits) $ (43.3 ) $ 13.5 $ 71.7 The provision for income taxes consists of: (in millions) 2015 2016 2017 Current income taxes U.S. federal $ 669.5 $ 573.7 $ 708.1 State and local 134.3 105.8 131.0 Foreign 18.9 13.5 13.1 Deferred income taxes (tax benefits) (43.3 ) 13.5 71.7 Total $ 779.4 $ 706.5 $ 923.9
Schedule of effective income tax rate reconciliation	The following table reconciles the statutory federal income tax rate to our effective income tax rate. 2015 2016 2017 Statutory U.S. federal income tax rate 35.0 % 35.0 % 35.0 % Impact of U.S. tax reform — — 2.9 State income taxes for current year, net of federal income tax benefits (1) 4.3 3.8 3.9 Net income attributable to redeemable non-controlling interests — (.7 ) (1.3 ) Net excess tax benefits from stock-based compensation plans activity — (1.7 ) (3.0 ) Other items (.4 ) (.4 ) (.6 ) Effective income tax rate 38.9 % 36.0 % 36.9 % (1) In 2017, state income benefits totaling (.4)% are reflected in the total benefits for net income attributable to redeemable non-controlling interests and stock-based compensation plans activity. The amounts were not material in 2015 and 2016 .
Schedule of deferred tax assets and liabilities	The net deferred tax assets recognized in our consolidated balance sheets in other assets as of December 31 relate to the following: (in millions) 2016 2017 Deferred tax liabilities Property and equipment $ (39.2 ) $ (35.3 ) Net unrealized holding gains recognized in income (43.2 ) (53.9 ) Net unrealized holding gains on investments held as available-for-sale (33.4 ) (3.1 ) Other (27.5 ) (18.9 ) (143.3 ) (111.2 ) Deferred tax assets Stock-based compensation 165.1 92.7 Asset impairments 16.1 8.8 Accrued compensation 5.6 4.4 Supplemental savings plan 58.3 66.6 Currency translation adjustment 23.0 2.2 Other 7.7 6.8 275.8 181.5 Net deferred tax asset $ 132.5 $ 70.3
Schedule of unrecognized tax benefits	The following table summarizes the changes in our unrecognized tax benefits. (in millions) 2015 2016 2017 Balance at beginning of year $ 5.6 $ 5.8 $ 6.2 Changes in tax positions related to Current year .7 .6 1.5 Prior years 1.8 — .1 Expired statute of limitations (2.3 ) (.2 ) (.2 ) Balance at end of year $ 5.8 $ 6.2 $ 7.6

STOCK-BASED COMPENSATION. (Tabl

STOCK-BASED COMPENSATION. (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Rollforward of stock options	The following table summarizes the status of, and changes in, our stock options during 2017 . Options Weighted- average exercise price Weighted-average remaining contractual term in years Outstanding at December 31, 2016 24,364,322 $ 61.90 Exercised (8,977,164 ) $ 53.04 Forfeited (126,404 ) $ 75.16 Expired (39,631 ) $ 76.06 Outstanding at December 31, 2017 15,221,123 $ 66.98 5.1 Exercisable at December 31, 2017 11,140,190 $ 63.79 4.5
Rollforward of nonvested restricted shares and restricted stock units	The following table summarizes the status of, and changes in, our nonvested restricted shares and restricted stock units during 2017 . Restricted shares Restricted stock units Weighted- average fair value Nonvested at December 31, 2016 931,508 4,634,461 $ 72.19 Time-based grants 17,022 2,026,176 $ 100.24 Performance-based grants — 114,454 $ 101.79 Vested (value at vest date was $164.5 million) (455,958 ) (1,111,857 ) $ 71.77 Forfeited (19,457 ) (106,323 ) $ 72.32 Nonvested at December 31, 2017 473,115 5,556,911 $ 82.37
Future stock-based compensation expense	The following table presents the compensation expense (in millions) to be recognized over the remaining vesting periods of the stock-based awards outstanding at December 31, 2017 . Estimated future compensation expense will change to reflect future grants changes in the probability of performance thresholds being met, and adjustments for actual forfeitures. First quarter 2018 $ 47.3 Second quarter 2018 46.7 Third quarter 2018 46.0 Fourth quarter 2018 40.3 Total 2018 180.3 2019 through 2023 176.1 Total $ 356.4

EARNINGS PER SHARE CALCULATIO35

EARNINGS PER SHARE CALCULATIONS. (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings per share reconciliation	The following table presents the reconciliation of net income attributable to T. Rowe Price Group to net income allocated to our common stockholders and the weighted-average shares that are used in calculating the basic and diluted earnings per share on our common stock. Weighted-average common shares outstanding assuming dilution reflect the potential dilution, determined using the treasury stock method, that could occur if outstanding stock options were exercised and non-participating stock awards vested. (in millions) 2015 2016 2017 Net income attributable to T. Rowe Price Group $ 1,223.0 $ 1,215.0 $ 1,497.8 Less: net income allocated to outstanding restricted stock and stock unit holders 16.1 25.5 33.9 Net income allocated to common stockholders $ 1,206.9 $ 1,189.5 $ 1,463.9 Weighted-average common shares Outstanding 254.6 245.5 241.2 Outstanding assuming dilution 260.9 250.3 245.1
Anti-dilutive securities	The following table shows the weighted-average outstanding stock options that are excluded from the calculation of diluted earnings per common share as the inclusion of such shares would be anti-dilutive. (in millions) 2015 2016 2017 Weighted-average outstanding stock options excluded 6.4 9.9 5.0

OTHER COMPREHENSIVE INCOME AN36

OTHER COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME. (Tables)	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
Impact of the components of other comprehensive income on deferred tax benefits (income taxes)	The following table presents the impact of the components of other comprehensive income or loss on deferred tax benefits (income taxes). (in millions) 2015 2016 2017 Net deferred tax benefits (income taxes) on: Net unrealized holding gains or losses $ 5.1 $ .6 $ (14.6 ) Reclassification adjustments recognized in the provision for income taxes: Capital gain distributions 7.9 2.4 1.4 Net gains realized on dispositions 20.7 20.9 32.5 Net gains recognized upon transfer to trading investments — — 9.2 Other-than-temporary impairments (1.9 ) — — Net deferred tax benefits (income taxes) on net unrealized holding gains or losses 31.8 23.9 28.5 Currency translation adjustments 3.8 3.5 (18.5 ) Reclassification adjustment recognized in the provision for income taxes upon deconsolidation of T. Rowe Price investment product (1.2 ) .8 — Total deferred tax benefits (income taxes) on currency translation adjustments 2.6 4.3 (18.5 ) Total net deferred tax benefits (income taxes) $ 34.4 $ 28.2 $ 10.0
Changes in accumulated other comprehensive income	The changes in each component of accumulated other comprehensive income (loss), including reclassification are presented below. Currency translation adjustments (in millions) Net unrealized holding gains Equity method investments Consolidated T. Rowe Price investment products - variable interest entities Total currency translation adjustments Total Balances at December 31, 2014 $ 165.5 $ (25.7 ) $ (3.4 ) $ (29.1 ) $ 136.4 Other comprehensive income (loss) before reclassifications and income taxes (4.5 ) (8.1 ) (4.9 ) (13.0 ) (17.5 ) Reclassification adjustments recognized in non-operating income (72.5 ) — 5.8 5.8 (66.7 ) (77.0 ) (8.1 ) .9 (7.2 ) (84.2 ) Net deferred tax benefits (income taxes) 31.8 2.9 (.3 ) 2.6 34.4 Other comprehensive income (loss) (45.2 ) (5.2 ) .6 (4.6 ) (49.8 ) Balances at December 31, 2015 120.3 (30.9 ) (2.8 ) (33.7 ) 86.6 Reclassification of accumulated other comprehensive income to retained earnings upon adoption of the new consolidation accounting guidance (32.0 ) (.5 ) — (.5 ) (32.5 ) Balance at January 1, 2016 88.3 (31.4 ) (2.8 ) (34.2 ) 54.1 Other comprehensive income (loss) before reclassifications and income taxes (7.0 ) (1.6 ) (7.0 ) (8.6 ) (15.6 ) Reclassification adjustments recognized in non-operating income (53.0 ) — (2.2 ) (2.2 ) (55.2 ) (60.0 ) (1.6 ) (9.2 ) (10.8 ) (70.8 ) Net deferred tax benefits (income taxes) 23.9 .7 3.6 4.3 28.2 Other comprehensive income (loss) (36.1 ) (.9 ) (5.6 ) (6.5 ) (42.6 ) Balances at December 31, 2016 52.2 (32.3 ) (8.4 ) (40.7 ) 11.5 Other comprehensive income (loss) before reclassifications and income taxes 37.4 2.6 45.2 47.8 85.2 Reclassification adjustments recognized in non-operating income (110.2 ) — (.1 ) (.1 ) (110.3 ) (72.8 ) 2.6 45.1 47.7 (25.1 ) Net deferred tax benefits (income taxes) 28.5 (.9 ) (17.6 ) (18.5 ) 10.0 Other comprehensive income (loss) (44.3 ) 1.7 27.5 29.2 (15.1 ) Balances at December 31, 2017 $ 7.9 $ (30.6 ) $ 19.1 $ (11.5 ) $ (3.6 )

SUPPLEMENTARY CONSOLIDATING C37

SUPPLEMENTARY CONSOLIDATING CASH FLOW STATEMENT. (Tables)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Supplementary consolidating cash flow statement	The following table summarizes the cash flows that are attributable to T. Rowe Price Group, our consolidated T. Rowe Price investment products , and the related eliminations required in preparing the statement. 2016 2017 (in millions) Cash flow attributable to T. Rowe Price Group Cash flow attributable to consolidated T. Rowe Price investment products Eliminations As reported Cash flow attributable to T. Rowe Price Group Cash flow attributable to consolidated T. Rowe Price investment products Eliminations As reported Cash flows from operating activities Net income $ 1,215.0 $ 108.1 $ (69.1 ) $ 1,254.0 $ 1,497.8 $ 181.6 $ (98.2 ) $ 1,581.2 Adjustments to reconcile net income to net cash provided by (used in) operating activities Depreciation and amortization of property and equipment 133.4 — — 133.4 143.6 — — 143.6 Stock-based compensation expense 161.6 — — 161.6 152.0 — — 152.0 Realized gains on dispositions of available-for-sale T. Rowe Price investment products (53.0 ) — — (53.0 ) (83.1 ) — — (83.1 ) Gains recognized upon transfer of an available-for-sale T. Rowe Price investment products to T. Rowe Price investment products held as trading — — — — (23.6 ) — — (23.6 ) Net gains recognized on investments (100.1 ) — 69.1 (31.0 ) (147.9 ) — 98.2 (49.7 ) Investments in T. Rowe Price mutual funds held as trading to economically hedge supplemental savings plan liability — — — — (218.6 ) — — (218.6 ) Net change in trading securities held by consolidated T. Rowe Price investment products — (1,297.9 ) — (1,297.9 ) — (1,492.9 ) — (1,492.9 ) Changes in accounts receivable and accrued revenue (9.3 ) — — (9.3 ) (100.8 ) — — (100.8 ) Changes in payables and accrued liabilities 101.5 37.1 — 138.6 169.1 154.3 — 323.4 Other changes in assets and liabilities (105.4 ) (13.9 ) (6.6 ) (125.9 ) 163.3 (158.3 ) (7.0 ) (2.0 ) Net cash provided by (used in) operating activities 1,343.7 (1,166.6 ) (6.6 ) 170.5 1,551.8 (1,315.3 ) (7.0 ) 229.5 Net cash provided by (used in) investing activities (219.7 ) 41.4 284.5 106.2 (33.9 ) (64.2 ) 137.1 39.0 Net cash used in financing activities attributable to T. Rowe Price Group (1,091.4 ) — — (1,091.4 ) (820.1 ) — — (820.1 ) Net subscriptions received from redeemable non-controlling interest holders — 1,192.9 (277.9 ) 915.0 — 1,411.7 (130.1 ) 1,281.6 Net cash provided by (used in) financing activities (1,091.4 ) 1,192.9 (277.9 ) (176.4 ) (820.1 ) 1,411.7 (130.1 ) 461.5 Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products — (2.1 ) — (2.1 ) — 5.3 — 5.3 Net change in cash and cash equivalents during period 32.6 65.6 — 98.2 697.8 37.5 — 735.3 Cash and cash equivalents at beginning of year 1,172.3 — — 1,172.3 1,204.9 65.6 — 1,270.5 Cash and cash equivalents at end of period $ 1,204.9 $ 65.6 $ — $ 1,270.5 $ 1,902.7 $ 103.1 $ — $ 2,005.8

SUPPLEMENTARY QUARTERLY FINAN38

SUPPLEMENTARY QUARTERLY FINANCIAL DATA (Unaudited). (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of supplementary quarterly financial data	Net revenues Net income (2) Net income attributable to T. Rowe Price Group (2) Basic earnings on common stock (1) Diluted earnings on common stock (1),(2) (in millions) (per share) 2016 1st quarter $ 994.1 $ 313.3 $ 304.1 $ 1.21 $ 1.18 2nd quarter $ 1,044.7 $ 211.2 $ 203.3 $ .81 $ .79 3rd quarter $ 1,092.9 $ 362.7 $ 327.8 $ 1.30 $ 1.28 4th quarter $ 1,091.2 $ 366.8 $ 379.8 $ 1.53 $ 1.50 2017 1st quarter $ 1,113.6 $ 400.4 $ 385.9 $ 1.56 $ 1.54 2nd quarter $ 1,171.6 $ 390.0 $ 373.9 $ 1.52 $ 1.50 3rd quarter $ 1,221.7 $ 404.2 $ 390.9 $ 1.59 $ 1.56 4th quarter $ 1,286.1 $ 386.6 $ 347.1 $ 1.40 $ 1.37 (1) The sums of quarterly earnings per share may not equal annual earnings per share because the computations are done independently. (2) The second quarter of 2016 includes a nonrecurring operating charge of $166.2 million , or $.39 in diluted earnings per share, related to our decision to compensate certain clients in regard to the Dell appraisal rights matter. In the fourth quarter of 2016, we recognized an offset to this charge for a related insurance recovery of $100 million , or $.24 in diluted earnings per share. During the first quarter of 2017, we recognized an additional $50 million in insurance recoveries, or $.12 in diluted earnings per share relating to the Dell matter. For more details related to the Dell appraisal rights matter, see Note 12 to the consolidated financial statements. During the fourth quarter of 2017, we recognized a nonrecurring charge of $71.1 million related to the U.S. tax law changes that were enacted on December 22, 2017. See Note 7 to the consolidated financial statements for further details.

SUMMARY OF SIGNIFICANT ACCOUN39

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES. (Basis of presentation) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017
Accounting Policies [Abstract]
Income tax provision related to the tax law changes	$ 71.1	$ 71.1
Income tax provision related to remeasurement of deferred tax assets and liabilities		18.9
Income tax provision related to mandatory deemed repatriation of foreign sourced net earnings		$ 52.2

SUMMARY OF SIGNIFICANT ACCOUN40

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES. (Newly issued but not yet adopted accounting guidance) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 01, 2018	Dec. 31, 2014
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of revenue related expenses to operating expenses									$ 2,684.2	$ 2,489.5	$ 2,301.7
Reclassification of revenue related expenses from revenue to operating expenses	$ 1,286.1	$ 1,221.7	$ 1,171.6	$ 1,113.6	$ 1,091.2	$ 1,092.9	$ 1,044.7	$ 994.1	4,793	4,222.9	4,200.6
Reclassification of unrealized holding gains recognized on investments from AOCI to retained earnings	5,824.4				5,008.6				5,824.4	5,008.6	4,762		$ 5,395.2
Pro forma [Member] | ASU 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of revenue related expenses to operating expenses									60	60
Reclassification of revenue related expenses from revenue to operating expenses									60	60
Net unrealized holding gains or losses [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of unrealized holding gains recognized on investments from AOCI to retained earnings	$ 7.9				$ 52.2				$ 7.9	$ 52.2	$ 120.3		$ 165.5
Subsequent event [Member] | Net unrealized holding gains or losses [Member] | ASU 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of unrealized holding gains recognized on investments from AOCI to retained earnings												$ (7.9)
Subsequent event [Member] | Retained earnings [Member] | ASU 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of unrealized holding gains recognized on investments from AOCI to retained earnings												$ 7.9

SUMMARY OF SIGNIFICANT ACCOUN41

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES. (Investments) (Details)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Duration of fund holding unrealized loss between quarter-ends generally presumed to represent other than temporary impairment	6 months

SUMMARY OF SIGNIFICANT ACCOUN42

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES. (Property and equipment) (Details)	12 Months Ended
	Dec. 31, 2017
Computer and communications software and equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Buildings and improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	32 years
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	8 years
Furniture and other equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years
Leased land [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	99 years

SUMMARY OF SIGNIFICANT ACCOUN43

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES. (Goodwill) (Details)	12 Months Ended
	Dec. 31, 2017reporting_unitSegment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of distinct operating segments through which we internally conduct and manage our operations	1
Number of distinct operating segments through which we report our operations	1
Number of reportable business segments and units to which goodwill is attributed (reporting unit) | reporting_unit	1

SUMMARY OF SIGNIFICANT ACCOUN44

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES. (Stock-based compensation) (Details)	12 Months Ended
	Dec. 31, 2017share_based_compensation_planshares	Dec. 31, 2016$ / shares	Dec. 31, 2015$ / shares
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Grant-date fair value per option awarded (in dollars per share) | $ / shares		$ 10.62	$ 17.35
Stock compensation plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant (shares) | shares	18,445,397
Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected life in years		6 years 9 months	7 years
Expected volatility		20.00%	27.00%
Dividend yield		2.50%	2.40%
Risk-free interest rate		1.60%	1.90%
Employee stock-based compensation programs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stockholder-approved plans (plans)	3
Employee stock-based compensation programs [Member] | Restricted shares and restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Graded vesting period	5 years
Employee stock-based compensation programs [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term	10 years
Non-employee director plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stockholder-approved plans (plans)	2
Graded vesting period	1 year
Non-employee director plans [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term	10 years

CASH EQUIVALENTS. (Details)

CASH EQUIVALENTS. (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash and Cash Equivalents [Abstract]
Cash equivalent investments in T. Rowe Price money market mutual funds	$ 1,726.4	$ 1,052.3
Money market mutual funds [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Dividends earned on money market mutual funds	$ 9.1	$ 0.3	$ 0.2

INFORMATION ABOUT RECEIVABLES46

INFORMATION ABOUT RECEIVABLES, REVENUES, AND SERVICES. (Receivables) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Receivables from sponsored mutual funds
Accounts receivable for advisory fees and advisory-related administrative services	$ 556.7	$ 455.1
T.Rowe Price U.S. mutual funds [Member]
Receivables from sponsored mutual funds
Accounts receivable for advisory fees and advisory-related administrative services	$ 365.3	$ 303.1

INFORMATION ABOUT RECEIVABLES47

INFORMATION ABOUT RECEIVABLES, REVENUES, AND SERVICES. (Investment Advisory Services) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue and Services [Line Items]
Revenues from advisory services	$ 4,287.7	$ 3,728.7	$ 3,687.3
Average assets under management	909,000	778,200	767,900
Period end assets under management	991,100	810,800
T. Rowe Price U.S. mutual funds [Member]
Revenue and Services [Line Items]
Revenues from advisory services	3,071.9	2,705.4	2,667.9
Average assets under management	568,500	495,500	493,600
Period end assets under management	606,300	514,200
T. Rowe Price U.S. mutual funds [Member] | Stock and blended asset [Member]
Revenue and Services [Line Items]
Revenues from advisory services	2,570.9	2,228.1	2,241.9
Average assets under management	447,500	386,100	387,800
Period end assets under management	480,500	401,300
T. Rowe Price U.S. mutual funds [Member] | Bond and money market [Member]
Revenue and Services [Line Items]
Revenues from advisory services	501	477.3	426
Average assets under management	121,000	109,400	105,800
Period end assets under management	125,800	112,900
Other investment products [Member]
Revenue and Services [Line Items]
Revenues from advisory services	1,215.8	1,023.3	1,019.4
Average assets under management	340,500	282,700	274,300
Period end assets under management	384,800	296,600
Other investment products [Member] | Stock and blended asset [Member]
Revenue and Services [Line Items]
Revenues from advisory services	1,009.4	850.3	862.2
Average assets under management	256,400	211,100	210,300
Period end assets under management	291,900	220,800
Other investment products [Member] | Bond, money market, and stable value [Member]
Revenue and Services [Line Items]
Revenues from advisory services	206.4	173	157.2
Average assets under management	84,100	71,600	64,000
Period end assets under management	92,900	75,800
Other T. Rowe Price investment products [Member]
Revenue and Services [Line Items]
Revenues from advisory services	$ 478.2	386	367.8
Waived money market related fees [Member]
Revenue and Services [Line Items]
Revenues from advisory services		$ 10.5	$ 47.6

INFORMATION ABOUT RECEIVABLES48

INFORMATION ABOUT RECEIVABLES, REVENUES, AND SERVICES. (Revenues and Services Concentration) (Details)	Dec. 31, 2017	Dec. 31, 2016
Outside U.S. [Member] | Assets under management [Member] | Investment advisory clients [Member] | Geographic concentration [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	5.80%	4.70%

INFORMATION ABOUT RECEIVABLES49

INFORMATION ABOUT RECEIVABLES, REVENUES, AND SERVICES. (Other Fees Earned from Sponsored U.S. Mutual Funds) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue and Services [Line Items]
Administrative fees	$ 358.3	$ 352.5	$ 361.8
Distribution and servicing fees	147	141.7	151.5
T. Rowe Price U.S. mutual funds [Member]
Revenue and Services [Line Items]
Administrative fees	283.1	277.3	292.8
Distribution and servicing fees	$ 147	$ 141.7	$ 151.5

INVESTMENTS. (Investments) (Det

INVESTMENTS. (Investments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investment [Line Items]
T. Rowe Price investment products held as available-for-sale	$ 597.1	$ 709
Cost method investments	78	73.6
U.S. Treasury note	1	1
Total	1,477.3	1,257.5
Gains (losses) recognized upon deconsolidation	396.3	227.1	$ 103.5
T. Rowe Price investment products [Member]
Investment [Line Items]
Equity method investments	277.4	252.3
Trading investments	95	75.4
T. Rowe Price investment products designated as an economic hedge of supplemental savings plan liability [Member]
Investment [Line Items]
Trading investments	268.2	0
Interest in UTI Asset Management Company Limited (India) [Member]
Investment [Line Items]
Equity method investments	$ 155.8	$ 140.9
Equity method investment (ownership percentage)	26.00%	26.00%
Investment partnerships [Member]
Investment [Line Items]
Equity method investments	$ 4.8	$ 5.3
Currency translation adjustments [Member] | Reclassification out of accumulated other comprehensive income [Member]
Investment [Line Items]
Gains (losses) recognized upon deconsolidation	0.1	2.2	(5.8)
Assets [Member]
Investment [Line Items]
Net increase (decrease) in assets, liabilities, and redeemable noncontrolling interest	1,397.2	1,342.8	20.3
Liability [Member]
Investment [Line Items]
Net increase (decrease) in assets, liabilities, and redeemable noncontrolling interest	(153.1)	(37.3)	0
Redeemable non-controlling interest [Member]
Investment [Line Items]
Net increase (decrease) in assets, liabilities, and redeemable noncontrolling interest	$ (1,042.6)	$ (967.3)	$ 0

INVESTMENTS. (T. Rowe Price Inv

INVESTMENTS. (T. Rowe Price Investment Product - Available for Sale) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Aggregate cost	$ 587.2	$ 626.2
Unrealized holding gains	14.4	89.7
Unrealized holding losses	(4.5)	(6.9)
Aggregate fair value	597.1	709
Stock and blended asset funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Aggregate cost	106.7	162.9
Unrealized holding gains	14.1	88
Unrealized holding losses	0	(1.9)
Aggregate fair value	120.8	249
Bond funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Aggregate cost	480.5	463.3
Unrealized holding gains	0.3	1.7
Unrealized holding losses	(4.5)	(5)
Aggregate fair value	$ 476.3	$ 460

INVESTMENTS. (Unrealized Losses

INVESTMENTS. (Unrealized Losses on Available-For-Sale T. Rowe Price Investment Portfolios) (Details) $ in Millions	Dec. 31, 2017USD ($)security	Dec. 31, 2016USD ($)security
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions [Abstract]
Number of holdings with unrealized holding losses less than 12 months (number of securities) | security	2	8
Number of holdings with unrealized holding losses 12 months or more (number of securities) | security	2	2
Total number of holdings with unrealized holding losses (number of securities) | security	4	10
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Unrealized holding losses of holdings that were in a continuous loss for less than 12 months	$ (0.4)	$ (4.2)
Unrealized holding losses of holdings that were in a continuous loss for 12 months or more	(4.1)	(2.7)
Total unrealized holding losses of holdings that were in a continuous loss	(4.5)	(6.9)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Aggregate fair value of holdings with unrealized holding losses for less than 12 months	213.2	328.1
Aggregate fair value of holdings with unrealized holding losses for 12 months or more	191.5	169.5
Total aggregate fair value of holdings with unrealized holding losses	$ 404.7	$ 497.6

INVESTMENTS. (Dividends) (Detai

INVESTMENTS. (Dividends) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Dividends excluding capital gain distributions [Member] | Available-for-sale sponsored investment portfolios [Member]
Net Investment Income [Line Items]
Dividends	$ 8.2	$ 8.7	$ 18.1

INVESTMENTS. (Variable Interest

INVESTMENTS. (Variable Interest Entities) (Details) - Variable interest entity, not primary beneficiary [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Investment carrying values	$ 129.2	$ 149.2
Unfunded capital commitments	38.8	46.4
Uncollected investment advisory and administrative fees	7.7	5.9
Maximum risk of loss related to nonconsolidated variable interest entities	$ 175.7	$ 201.5

FAIR VALUE MEASUREMENTS. (Detai

FAIR VALUE MEASUREMENTS. (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
T. Rowe Price investment products held as available-for-sale	$ 597.1	$ 709
Level 1 [Member] | Fair value, measurements, recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	1,726.4	1,052.3
T. Rowe Price investment products held as available-for-sale	597.1	709
T. Rowe Price investment products held as trading	345.8	60.3
Total	2,669.3	1,821.6
Level 2 [Member] | Fair value, measurements, recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
T. Rowe Price investment products held as available-for-sale	0	0
T. Rowe Price investment products held as trading	17.4	15.1
Total	$ 17.4	$ 15.1

CONSOLIDATED T. ROWE PRICE IN56

CONSOLIDATED T. ROWE PRICE INVESTMENT PRODUCTS. (Net Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 1,902,700	$ 1,204,900
Investments	1,477,300	1,257,500
Other assets	231,900	346,200
Total assets	7,534,700	6,225,000
Liabilities	717,500	529,200
Attributable to redeemable non-controlling interests	992,800	687,200	$ 0	$ 0
Consolidated T. Rowe Price investment products [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	103,100	65,600
Net assets	1,992,500	1,614,900
Attributable to redeemable non-controlling interests	992,800	687,200
Attributable to T. Rowe Price Group	999,700	927,700
Consolidated T. Rowe Price investment products [Member] | Reportable entities [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	103,100	65,600	0
Investments	1,914,500	1,559,900
Other assets	30,800	55,000
Total assets	2,048,400	1,680,500
Liabilities	55,900	65,600
Net assets	1,992,500	1,614,900
Voting interest entities [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Net assets	192,400	225,600
Attributable to redeemable non-controlling interests	60,800	69,500
Attributable to T. Rowe Price Group	131,600	156,100
Voting interest entities [Member] | Reportable entities [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	7,100	10,300	0
Investments	188,800	219,300
Other assets	12,900	4,800
Total assets	208,800	234,400
Liabilities	16,400	8,800
Net assets	192,400	225,600
Variable interest entities [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Net assets	1,800,100	1,389,300
Attributable to redeemable non-controlling interests	932,000	617,700
Attributable to T. Rowe Price Group	868,100	771,600
Variable interest entities [Member] | Reportable entities [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	96,000	55,300	$ 0
Investments	1,725,700	1,340,600
Other assets	17,900	50,200
Total assets	1,839,600	1,446,100
Liabilities	39,500	56,800
Net assets	1,800,100	1,389,300
T.Rowe Price U.S. mutual funds [Member] | Consolidated T. Rowe Price investment products [Member] | Reportable entities [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	6,200	8,800
Investments	$ 15,000	$ 4,200

CONSOLIDATED T. ROWE PRICE IN57

CONSOLIDATED T. ROWE PRICE INVESTMENT PRODUCTS. (Operating Results) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Income Statements, Captions [Line Items]
Operating expenses									$ (2,684.2)	$ (2,489.5)	$ (2,301.7)
Income before income taxes									2,505.1	1,960.5	2,002.4
Net income attributable to redeemable non-controlling interests									83.4	39	0
Investment advisory and administrative fees	$ (1,286.1)	$ (1,221.7)	$ (1,171.6)	$ (1,113.6)	$ (1,091.2)	$ (1,092.9)	$ (1,044.7)	$ (994.1)	(4,793)	(4,222.9)	$ (4,200.6)
Consolidation eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Operating expenses									5.6	6.5
Investment advisory and administrative fees									5.6	6.5
Consolidated T. Rowe Price investment products [Member]
Condensed Income Statements, Captions [Line Items]
Income before income taxes									181.6	108.1
Net income attributable to T. Rowe Price Group									98.2	69.1
Net income attributable to redeemable non-controlling interests									83.4	39
Consolidated T. Rowe Price investment products [Member] | Reportable entities [Member]
Condensed Income Statements, Captions [Line Items]
Operating expenses									(12.3)	(13)
Net investment non-operating income									193.9	121.1
Income before income taxes									181.6	108.1
Voting interest entities [Member]
Condensed Income Statements, Captions [Line Items]
Income before income taxes									17.7	20.9
Net income attributable to T. Rowe Price Group									13.3	15
Net income attributable to redeemable non-controlling interests									4.4	5.9
Voting interest entities [Member] | Reportable entities [Member]
Condensed Income Statements, Captions [Line Items]
Operating expenses									(1.1)	(1.6)
Net investment non-operating income									18.8	22.5
Income before income taxes									17.7	20.9
Variable interest entities [Member]
Condensed Income Statements, Captions [Line Items]
Income before income taxes									163.9	87.2
Net income attributable to T. Rowe Price Group									84.9	54.1
Net income attributable to redeemable non-controlling interests									79	33.1
Variable interest entities [Member] | Reportable entities [Member]
Condensed Income Statements, Captions [Line Items]
Operating expenses									(11.2)	(11.4)
Net investment non-operating income									175.1	98.6
Income before income taxes									$ 163.9	$ 87.2

CONSOLIDATED T. ROWE PRICE IN58

CONSOLIDATED T. ROWE PRICE INVESTMENT PRODUCTS. (Statement of Cash Flows) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	[1]	$ 229.5	$ 170.5	$ 1,530.5
Net cash provided by (used in) investing activities	[1]	39	106.2	109
Net cash provided by (used in) financing activities	[1]	461.5	(176.4)	(1,973.3)
Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products	[1]	5.3	(2.1)	0
Net change in cash and cash equivalents during period	[1]	735.3	98.2	(333.8)
Cash and cash equivalents at beginning of year		1,204.9
Cash and cash equivalents at end of year		1,902.7	1,204.9
Consolidation eliminations [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities		(7)	(6.6)
Net cash provided by (used in) investing activities		137.1	284.5
Net cash provided by (used in) financing activities		(130.1)	(277.9)
Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products		0	0
Net change in cash and cash equivalents during period		0	0
Consolidated T. Rowe Price investment products [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents at beginning of year		65.6
Cash and cash equivalents at end of year		103.1	65.6
Consolidated T. Rowe Price investment products [Member] | Reportable entities [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities		(1,315.3)	(1,166.6)
Net cash provided by (used in) investing activities		(64.2)	41.4
Net cash provided by (used in) financing activities		1,411.7	1,192.9
Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products		5.3	(2.1)
Net change in cash and cash equivalents during period		37.5	65.6
Cash and cash equivalents at beginning of year		65.6	0
Cash and cash equivalents at end of year		103.1	65.6	0
Voting interest entities [Member] | Reportable entities [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities		(33)	(80.1)
Net cash provided by (used in) investing activities		(9)	21.6
Net cash provided by (used in) financing activities		38.8	68.8
Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products		0	0
Net change in cash and cash equivalents during period		(3.2)	10.3
Cash and cash equivalents at beginning of year		10.3	0
Cash and cash equivalents at end of year		7.1	10.3	0
Variable interest entities [Member] | Reportable entities [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities		(1,282.3)	(1,086.5)
Net cash provided by (used in) investing activities		(55.2)	19.8
Net cash provided by (used in) financing activities		1,372.9	1,124.1
Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products		5.3	(2.1)
Net change in cash and cash equivalents during period		40.7	55.3
Cash and cash equivalents at beginning of year		55.3	0
Cash and cash equivalents at end of year		$ 96	$ 55.3	$ 0
[1]	See note 15 for a supplementary consolidating cash flow schedule.

CONSOLIDATED T. ROWE PRICE IN59

CONSOLIDATED T. ROWE PRICE INVESTMENT PRODUCTS. (Fair Value Measurements) (Details) - Fair value, measurements, recurring [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 1,726.4	$ 1,052.3
Trading investments	345.8	60.3
Total	2,669.3	1,821.6
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Trading investments	17.4	15.1
Total	17.4	15.1
Consolidated T. Rowe Price investment products [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	6.2	8.8
Total	543.5	291
Liabilities	(0.1)	(0.6)
Consolidated T. Rowe Price investment products [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0.7	0.8
Total	1,377.9	1,278.5
Liabilities	(13.7)	(13.6)
Consolidated T. Rowe Price investment products [Member] | Equity securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading investments	536	281.8
Consolidated T. Rowe Price investment products [Member] | Equity securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading investments	667.5	325.3
Consolidated T. Rowe Price investment products [Member] | Fixed income securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading investments	0	0
Consolidated T. Rowe Price investment products [Member] | Fixed income securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading investments	687.4	918.1
Consolidated T. Rowe Price investment products [Member] | Other investments [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading investments	1.3	0.4
Consolidated T. Rowe Price investment products [Member] | Other investments [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading investments	$ 22.3	$ 34.3

PROPERTY AND EQUIPMENT. (Owned)

PROPERTY AND EQUIPMENT. (Owned) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,596.9	$ 1,435.5
Less accumulated depreciation and amortization	944.9	820.4
Total	652	615.1
Computer and communications software and equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	824.4	704
Buildings and improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	442.5	422
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	121	108.2
Furniture and other equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	168.9	158.3
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	37.4	40.3
Leased land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2.7	2.7
Compensation and related costs attributable to the development of computer software for internal use [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, additions	$ 62.3	$ 28.9	$ 22.3

PROPERTY AND EQUIPMENT. (Leased

PROPERTY AND EQUIPMENT. (Leased) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Rental expense	$ 36	$ 32.8	$ 31.1
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Future minimum operating lease payments, due in 2018	37.8
Future minimum operating lease payments, due in 2019	37.2
Future minimum operating lease payments, due in 2020	32.9
Future minimum operating lease payments, due in 2021	29.6
Future minimum operating lease payments, due in 2022	24.6
Future minimum operating lease payments, due in later years	$ 100.5

INCOME TAXES. (Provision for In

INCOME TAXES. (Provision for Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	$ 708.1	$ 573.7	$ 669.5
State and local	131	105.8	134.3
Foreign	13.1	13.5	18.9
Deferred income taxes (tax benefits)	71.7	13.5	(43.3)
Total	$ 923.9	$ 706.5	$ 779.4

INCOME TAXES. (Narrative) (Deta

INCOME TAXES. (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Unremitted earnings of foreign subsidiaries	$ 604	$ 604
Tax refund receivables	43.2	43.2	$ 8.1
Net income taxes paid		857.7	680.6	$ 778.6
Additional income tax benefit arising from stock-based compensation				$ 23.2
Net tax benefits reducing income tax provision		75.5	31.6
Net interest payable related to unrecognized tax benefits	1.5	1.5	$ 1.2
Income tax provision related to the tax law changes	$ 71.1	71.1
Income tax provision related to remeasurement of deferred tax assets and liabilities		18.9
Income tax provision related to mandatory deemed repatriation of foreign sourced net earnings		$ 52.2

INCOME TAXES. (Deferred Income

INCOME TAXES. (Deferred Income Taxes (Tax Benefits)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Property and equipment	$ (3.9)	$ 3.2	$ (2.3)
Stock-based compensation	72.4	1.3	(14.6)
Accrued compensation	1.2	(1.7)	(0.9)
Supplemental savings plan liability	(8.3)	(30.9)	(27.4)
Other-than-temporary impairments of available-for-sale investments	7.3	10	(0.4)
Unrealized holding gains recognized in non-operating income	10.7	31.6	(2.4)
Other	(7.7)	0	4.7
Total deferred income taxes (tax benefits)	$ 71.7	$ 13.5	$ (43.3)

INCOME TAXES. (Effective Income

INCOME TAXES. (Effective Income Tax Rate Reconciliation) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Statutory U.S. federal income tax rate	35.00%	35.00%	35.00%
Impact of U.S. tax reform	2.90%	0.00%	0.00%
State income taxes for current year, net of federal income tax benefits	3.90%	3.80%	4.30%
Net income attributable to redeemable non-controlling interests	(1.30%)	(0.70%)	(0.00%)
Net excess tax benefits from stock-based compensation plans activity	(3.00%)	(1.70%)	(0.00%)
Other items	(0.60%)	(0.40%)	(0.40%)
Effective income tax rate	36.90%	36.00%	38.90%
State income tax benefit related to redeemable non-controlling interests and stock-based compensation	(0.40%)

INCOME TAXES. (Net Deferred Tax

INCOME TAXES. (Net Deferred Tax Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred tax liabilities
Property and equipment	$ (35.3)	$ (39.2)
Net unrealized holding gains recognized in income	(53.9)	(43.2)
Net unrealized holding gains on investments held as available-for-sale	(3.1)	(33.4)
Other	(18.9)	(27.5)
Total deferred tax liabilities	(111.2)	(143.3)
Deferred tax assets
Stock-based compensation	92.7	165.1
Asset impairments	8.8	16.1
Accrued compensation	4.4	5.6
Supplemental savings plan	66.6	58.3
Currency translation adjustment	2.2	23
Other	6.8	7.7
Total deferred tax assets	181.5	275.8
Net deferred tax asset	$ 70.3	$ 132.5

INCOME TAXES. (Changes in Unrec

INCOME TAXES. (Changes in Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 6.2	$ 5.8	$ 5.6
Changes in tax positions related to current year	1.5	0.6	0.7
Changes in tax positions related to prior years	0.1	0	1.8
Changes in tax positions related to expired statute of limitations	(0.2)	(0.2)	(2.3)
Balance at end of year	$ 7.6	$ 6.2	$ 5.8

STOCKHOLDERS' EQUITY. (Details)

STOCKHOLDERS' EQUITY. (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stockholders' Equity Note [Line Items]
Common shares authorized for future repurchase (shares)	15,183,779
Restricted stockholders' equity	$ 142
Regular cash dividend [Member]
Stockholders' Equity Note [Line Items]
Cash dividends declared per share	$ 2.28	$ 2.16	$ 2.08
Special cash dividend [Member]
Stockholders' Equity Note [Line Items]
Cash dividends declared per share			2
Cash dividends paid per share			$ 2

STOCK-BASED COMPENSATION. (Deta

STOCK-BASED COMPENSATION. (Details)	Dec. 31, 2017shares
Stock compensation plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock authorized for issuance (in shares)	39,301,717
Employee stock purchase [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock authorized for issuance (in shares)	2,693,678.7850

STOCK-BASED COMPENSATION. (Stoc

STOCK-BASED COMPENSATION. (Stock Options) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at December 31, 2016 (in shares)	24,364,322
Exercised (in shares)	(8,977,164)
Forfeited (in shares)	(126,404)
Expired (in shares)	(39,631)
Outstanding at December 31, 2017 (in shares)	15,221,123	24,364,322
Exercisable at December 31, 2017 (in shares)	11,140,190
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted-average exercise price of options outstanding at December 31, 2016 (in dollars per share)	$ 61.90
Weighted-average exercise price of options exercised (in dollars per share)	53.04
Weighted-average exercise price of options forfeited (in dollars per share)	75.16
Weighted-average exercise price of options expired (in dollars per share)	76.06
Weighted-average exercise price of options outstanding at December 31, 2017 (in dollars per share)	66.98	$ 61.90
Weighted-average exercise price of options exercisable at December 31, 2017 (in dollars per share)	$ 63.79
Weighted-average remaining contractual term in years, outstanding	5 years 1 month
Weighted-average remaining contractual term in years, exercisable	4 years 6 months
Total intrinsic value of options exercised	$ 293	$ 150.5	$ 108.1
Aggregate intrinsic value of in-the-money options outstanding	577.6
Aggregate intrinsic value of options exercisable	458.3
Compensation and related costs [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Stock-based compensation expense	$ 28.1	$ 44.9	$ 63.7

STOCK-BASED COMPENSATION. (Rest

STOCK-BASED COMPENSATION. (Restricted Shares and Stock Units) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average fair value of nonvested restricted shares and restricted stock units at December 31, 2016 (in dollars per share)	$ 72.19
Weighted-average fair value of restricted shares and restricted stock units vested (in dollars per share)	71.77
Weighted-average fair value of restricted shares and restricted stock units forfeited (in dollars per share)	72.32
Weighted-average fair value of nonvested restricted shares and restricted stock units at December 31, 2017 (in dollars per share)	$ 82.37	$ 72.19
Value at vest date	$ 164.5
Vested stock units (in shares)	78,286
Time-based [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average fair value of restricted shares and restricted stock units granted (in dollars per share)	$ 100.24
Performance-based [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average fair value of restricted shares and restricted stock units granted (in dollars per share)	$ 101.79
Restricted shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested at December 31, 2016 (in shares)	931,508
Vested (in shares)	(455,958)
Forfeited (in shares)	(19,457)
Nonvested at December 31, 2017 (in shares)	473,115	931,508
Restricted shares [Member] | Time-based [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Grants (in shares)	17,022
Restricted shares [Member] | Performance-based [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Grants (in shares)	0
Nonvested at December 31, 2017 (in shares)	7,200
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Nonvested shares where performance threshold has been met (in shares)	7,200
Restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested at December 31, 2016 (in shares)	4,634,461
Vested (in shares)	(1,111,857)
Forfeited (in shares)	(106,323)
Nonvested at December 31, 2017 (in shares)	5,556,911	4,634,461
Restricted stock units [Member] | Time-based [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Grants (in shares)	2,026,176
Restricted stock units [Member] | Performance-based [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Grants (in shares)	114,454
Nonvested at December 31, 2017 (in shares)	407,808
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Nonvested shares where performance threshold has been met (in shares)	293,354
Compensation and related costs [Member] | Restricted shares and restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Stock-based compensation expense	$ 124	$ 116.7	$ 85.3

STOCK-BASED COMPENSATION. (Futu

STOCK-BASED COMPENSATION. (Future Stock-Based Compensation Expense) (Details) $ in Millions	Dec. 31, 2017USD ($)
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
First quarter 2018	$ 47.3
Second quarter 2018	46.7
Third quarter 2018	46
Fourth quarter 2018	40.3
Total 2,018	180.3
2019 through 2023	176.1
Total	$ 356.4

EARNINGS PER SHARE CALCULATIO73

EARNINGS PER SHARE CALCULATIONS. (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income attributable to T. Rowe Price Group	$ 347.1	$ 390.9	$ 373.9	$ 385.9	$ 379.8	$ 327.8	$ 203.3	$ 304.1	$ 1,497.8	$ 1,215	$ 1,223
Less: net income allocated to outstanding restricted stock and stock unit holders (basic)									33.9	25.5	16.1
Less: net income allocated to outstanding restricted stock and stock unit holders (diluted)									33.9	25.5	16.1
Net income allocated to common stockholders (basic)									1,463.9	1,189.5	1,206.9
Net income allocated to common stockholders (diluted)									$ 1,463.9	$ 1,189.5	$ 1,206.9
Weighted-average common shares
Outstanding (in shares)									241.2	245.5	254.6
Outstanding assuming dilution (in shares)									245.1	250.3	260.9
Weighted-average outstanding stock options excluded (in shares)									5	9.9	6.4

OTHER COMPREHENSIVE INCOME AN74

OTHER COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME. (Deferred Tax Benefits (Income Taxes)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net unrealized holding gains or losses [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net deferred tax benefits (income taxes) on other comprehensive income before reclassifications	$ (14.6)	$ 0.6	$ 5.1
Total net deferred tax benefits (income taxes)	28.5	23.9	31.8
Capital gain distributions [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net deferred tax benefits (income taxes) on reclassifications from AOCI	1.4	2.4	7.9
Net gains realized on dispositions [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net deferred tax benefits (income taxes) on reclassifications from AOCI	32.5	20.9	20.7
Net gains recognized upon transfer to trading investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net deferred tax benefits (income taxes) on reclassifications from AOCI	9.2	0	0
Other-than-temporary impairments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net deferred tax benefits (income taxes) on reclassifications from AOCI	0	0	(1.9)
Currency translation adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net deferred tax benefits (income taxes) on other comprehensive income before reclassifications	(18.5)	3.5	3.8
Net deferred tax benefits (income taxes) on reclassifications from AOCI	0	0.8	(1.2)
Total net deferred tax benefits (income taxes)	(18.5)	4.3	2.6
Total accumulated other comprehensive income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total net deferred tax benefits (income taxes)	$ 10	$ 28.2	$ 34.4

OTHER COMPREHENSIVE INCOME AN75

OTHER COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME. (Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances	$ 5,008.6	$ 4,762	$ 5,395.2
Balances, Adjusted			4,765.9
Other comprehensive income (loss)	(15.1)	(42.6)	(49.8)
Balances	5,824.4	5,008.6	4,762
Net unrealized holding gains [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances	52.2	120.3	165.5
Other comprehensive income (loss) before reclassifications and income taxes	37.4	(7)	(4.5)
Reclassification adjustments recognized in non-operating income	(110.2)	(53)	(72.5)
Other comprehensive income (loss), before taxes	(72.8)	(60)	(77)
Net deferred tax benefits (income taxes)	28.5	23.9	31.8
Other comprehensive income (loss)	(44.3)	(36.1)	(45.2)
Balances	7.9	52.2	120.3
Net unrealized holding gains [Member] | Accounting standards update 2015-2 [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification of accumulated other comprehensive income to retained earnings upon adoption of the new consolidation accounting guidance			(32)
Balances, Adjusted			88.3
Currency translation adjustments [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances	(40.7)	(33.7)	(29.1)
Other comprehensive income (loss) before reclassifications and income taxes	47.8	(8.6)	(13)
Reclassification adjustments recognized in non-operating income	(0.1)	(2.2)	5.8
Other comprehensive income (loss), before taxes	47.7	(10.8)	(7.2)
Net deferred tax benefits (income taxes)	(18.5)	4.3	2.6
Other comprehensive income (loss)	29.2	(6.5)	(4.6)
Balances	(11.5)	(40.7)	(33.7)
Currency translation adjustments [Member] | Accounting standards update 2015-2 [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification of accumulated other comprehensive income to retained earnings upon adoption of the new consolidation accounting guidance			(0.5)
Balances, Adjusted			(34.2)
Currency translation adjustments [Member] | Equity method investments [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances	(32.3)	(30.9)	(25.7)
Other comprehensive income (loss) before reclassifications and income taxes	2.6	(1.6)	(8.1)
Reclassification adjustments recognized in non-operating income	0	0	0
Other comprehensive income (loss), before taxes	2.6	(1.6)	(8.1)
Net deferred tax benefits (income taxes)	(0.9)	0.7	2.9
Other comprehensive income (loss)	1.7	(0.9)	(5.2)
Balances	(30.6)	(32.3)	(30.9)
Currency translation adjustments [Member] | Equity method investments [Member] | Accounting standards update 2015-2 [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification of accumulated other comprehensive income to retained earnings upon adoption of the new consolidation accounting guidance			(0.5)
Balances, Adjusted			(31.4)
Currency translation adjustments [Member] | Consolidated T. Rowe Price investment products - variable interest entities [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances	(8.4)	(2.8)	(3.4)
Other comprehensive income (loss) before reclassifications and income taxes	45.2	(7)	(4.9)
Reclassification adjustments recognized in non-operating income	(0.1)	(2.2)	5.8
Other comprehensive income (loss), before taxes	45.1	(9.2)	0.9
Net deferred tax benefits (income taxes)	(17.6)	3.6	(0.3)
Other comprehensive income (loss)	27.5	(5.6)	0.6
Balances	19.1	(8.4)	(2.8)
Currency translation adjustments [Member] | Consolidated T. Rowe Price investment products - variable interest entities [Member] | Accounting standards update 2015-2 [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification of accumulated other comprehensive income to retained earnings upon adoption of the new consolidation accounting guidance			0
Balances, Adjusted			(2.8)
Total accumulated other comprehensive income [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances	11.5	86.6	136.4
Balances, Adjusted			54.1
Other comprehensive income (loss) before reclassifications and income taxes	85.2	(15.6)	(17.5)
Reclassification adjustments recognized in non-operating income	(110.3)	(55.2)	(66.7)
Other comprehensive income (loss), before taxes	(25.1)	(70.8)	(84.2)
Net deferred tax benefits (income taxes)	10	28.2	34.4
Other comprehensive income (loss)	(15.1)	(42.6)	(49.8)
Balances	$ (3.6)	$ 11.5	86.6
Total accumulated other comprehensive income [Member] | Accounting standards update 2015-2 [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification of accumulated other comprehensive income to retained earnings upon adoption of the new consolidation accounting guidance			(32.5)
Balances, Adjusted			$ 54.1

OTHER COMPREHENSIVE INCOME AN76

OTHER COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME. (Reclassification Adjustments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating income	$ (396.3)	$ (227.1)	$ (103.5)
Provision for income taxes	923.9	706.5	779.4
Net unrealized holding gains or losses [Member] | Reclassification out of accumulated other comprehensive income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating income	(110.2)	(53)	(72.5)
Capital gain distributions [Member] | Reclassification out of accumulated other comprehensive income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Provision for income taxes	1.4	2.4	7.9
Net gains realized on dispositions [Member] | Reclassification out of accumulated other comprehensive income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Provision for income taxes	32.5	20.9	20.7
Net gains recognized upon transfer to trading investments [Member] | Reclassification out of accumulated other comprehensive income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Provision for income taxes	9.2	0	0
Other-than-temporary impairments [Member] | Reclassification out of accumulated other comprehensive income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Provision for income taxes	0	0	(1.9)
Currency translation adjustments [Member] | Reclassification out of accumulated other comprehensive income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating income	(0.1)	(2.2)	5.8
Provision for income taxes	0	0.8	(1.2)
Total accumulated other comprehensive income [Member] | Reclassification out of accumulated other comprehensive income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating income	(110.3)	(55.2)	(66.7)
Variable interest entities [Member] | Currency translation adjustments [Member] | Reclassification out of accumulated other comprehensive income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-operating income	$ (0.1)	$ (2.2)	$ 5.8

DELL APPRAISAL RIGHTS MATTER. (

DELL APPRAISAL RIGHTS MATTER. (Details) - USD ($) $ / shares in Units, $ in Millions	Dec. 30, 2016	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2017
Dell appraisal rights matter [Member]
Unusual or Infrequent Item, or Both [Line Items]
Nonrecurring charge related to Dell appraisal rights matter				$ 166.2	$ 166.2
Court determined fair value per share at time of Dell merger (in dollars per share)				$ 17.62
Price offered per share in Dell merger (in dollars per share)				13.75
Payment per share for any shareholder perfecting appraisal rights (in dollars per share)				$ 17.62
Insurance proceeds	$ 100	$ 50	$ 100
Dell appraisal rights matter [Member]
Unusual or Infrequent Item, or Both [Line Items]
Unrecorded gain contingency						$ 15.2

OTHER DISCLOSURES. (Details)

OTHER DISCLOSURES. (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Expense recognized for defined contribution retirement plans	$ 89.4	$ 80.7	$ 74.9
Senior officers [Member] | Supplemental Savings Plan [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Supplemental Savings Plan, minimum deferral period	2 years
Supplemental Savings Plan, maximum deferral period	15 years
Amount of cash incentive compensation senior officers elected to defer	$ 95.5	$ 83.4	$ 72.8
Maximum [Member] | Senior officers [Member] | Supplemental Savings Plan [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Deferral percentage of cash incentive compensation	100.00%

SUPPLEMENTARY CONSOLIDATING C79

SUPPLEMENTARY CONSOLIDATING CASH FLOW STATEMENT. (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Net income		$ 386.6	$ 404.2	$ 390	$ 400.4	$ 366.8	$ 362.7	$ 211.2	$ 313.3	$ 1,581.2	[1]	$ 1,254	[1]	$ 1,223	[1]
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation and amortization of property and equipment	[1]									143.6		133.4		126.3
Stock-based compensation expense	[1]									152		161.6		149
Realized gains on dispositions of available-for-sale sponsored investment portfolios	[1]									(83.1)		(53)		(56.5)
Gains recognized upon transfer of an available-for-sale T. Rowe Price investment products to T. Rowe Price investment products held as trading	[1]									(23.6)		0		0
Net gains recognized on investments	[1]									(49.7)		(31)		(5.9)
Investments in T. Rowe Price mutual funds held as trading to economically hedge supplemental savings plan liability	[1]									(218.6)		0		0
Net change in trading securities held by consolidated T. Rowe Price investment products	[1]									(1,492.9)		(1,297.9)		(7.5)
Changes in accounts receivable and accrued revenue	[1]									(100.8)		(9.3)		(3.2)
Changes in payables and accrued liabilities	[1]									323.4		138.6		98.2
Other changes in assets and liabilities	[1]									(2)		(125.9)		7.1
Net cash provided by (used in) operating activities	[1]									229.5		170.5		1,530.5
Net cash provided by (used in) investing activities	[1]									39		106.2		109
Net cash provided by (used in) financing activities	[1]									461.5		(176.4)		(1,973.3)
Net subscriptions received from redeemable non-controlling interest holders	[1]									1,281.6		915		0
Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products	[1]									5.3		(2.1)		0
Net change in cash and cash equivalents during period	[1]									735.3		98.2		(333.8)
Cash and cash equivalents at beginning of year	[1]				1,270.5				1,172.3	1,270.5		1,172.3		1,506.1
Cash and cash equivalents at end of year	[1]	2,005.8				1,270.5				2,005.8		1,270.5		1,172.3
Consolidation eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net income										(98.2)		(69.1)
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation and amortization of property and equipment										0		0
Stock-based compensation expense										0		0
Realized gains on dispositions of available-for-sale sponsored investment portfolios										0		0
Gains recognized upon transfer of an available-for-sale T. Rowe Price investment products to T. Rowe Price investment products held as trading										0		0
Net gains recognized on investments										98.2		69.1
Investments in T. Rowe Price mutual funds held as trading to economically hedge supplemental savings plan liability										0		0
Net change in trading securities held by consolidated T. Rowe Price investment products										0		0
Changes in accounts receivable and accrued revenue										0		0
Changes in payables and accrued liabilities										0		0
Other changes in assets and liabilities										(7)		(6.6)
Net cash provided by (used in) operating activities										(7)		(6.6)
Net cash provided by (used in) investing activities										137.1		284.5
Net cash provided by (used in) financing activities										(130.1)		(277.9)
Net subscriptions received from redeemable non-controlling interest holders										(130.1)		(277.9)
Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products										0		0
Net change in cash and cash equivalents during period										0		0
Cash and cash equivalents at beginning of year					0				0	0		0
Cash and cash equivalents at end of year		0				0				0		0		0
Attributable to T. Rowe Price Group [Member] | Reportable entities [Member]
Condensed Financial Statements, Captions [Line Items]
Net income										1,497.8		1,215
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation and amortization of property and equipment										143.6		133.4
Stock-based compensation expense										152		161.6
Realized gains on dispositions of available-for-sale sponsored investment portfolios										(83.1)		(53)
Gains recognized upon transfer of an available-for-sale T. Rowe Price investment products to T. Rowe Price investment products held as trading										(23.6)		0
Net gains recognized on investments										(147.9)		(100.1)
Investments in T. Rowe Price mutual funds held as trading to economically hedge supplemental savings plan liability										(218.6)		0
Net change in trading securities held by consolidated T. Rowe Price investment products										0		0
Changes in accounts receivable and accrued revenue										(100.8)		(9.3)
Changes in payables and accrued liabilities										169.1		101.5
Other changes in assets and liabilities										163.3		(105.4)
Net cash provided by (used in) operating activities										1,551.8		1,343.7
Net cash provided by (used in) investing activities										(33.9)		(219.7)
Net cash provided by (used in) financing activities	[1]									(820.1)		(1,091.4)
Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products										0		0
Net change in cash and cash equivalents during period										697.8		32.6
Cash and cash equivalents at beginning of year					1,204.9				1,172.3	1,204.9		1,172.3
Cash and cash equivalents at end of year		1,902.7				1,204.9				1,902.7		1,204.9		1,172.3
Consolidated T. Rowe Price investment products [Member] | Reportable entities [Member]
Condensed Financial Statements, Captions [Line Items]
Net income										181.6		108.1
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation and amortization of property and equipment										0		0
Stock-based compensation expense										0		0
Realized gains on dispositions of available-for-sale sponsored investment portfolios										0		0
Gains recognized upon transfer of an available-for-sale T. Rowe Price investment products to T. Rowe Price investment products held as trading										0		0
Net gains recognized on investments										0		0
Investments in T. Rowe Price mutual funds held as trading to economically hedge supplemental savings plan liability										0		0
Net change in trading securities held by consolidated T. Rowe Price investment products										(1,492.9)		(1,297.9)
Changes in accounts receivable and accrued revenue										0		0
Changes in payables and accrued liabilities										154.3		37.1
Other changes in assets and liabilities										(158.3)		(13.9)
Net cash provided by (used in) operating activities										(1,315.3)		(1,166.6)
Net cash provided by (used in) investing activities										(64.2)		41.4
Net cash provided by (used in) financing activities										1,411.7		1,192.9
Net subscriptions received from redeemable non-controlling interest holders										1,411.7		1,192.9
Effect of exchange rate changes on cash and cash equivalents of consolidated T. Rowe Price investment products										5.3		(2.1)
Net change in cash and cash equivalents during period										37.5		65.6
Cash and cash equivalents at beginning of year					$ 65.6				$ 0	65.6		0
Cash and cash equivalents at end of year		$ 103.1				$ 65.6				$ 103.1		$ 65.6		$ 0
[1]	See note 15 for a supplementary consolidating cash flow schedule.

SUPPLEMENTARY QUARTERLY FINAN80

SUPPLEMENTARY QUARTERLY FINANCIAL DATA (Unaudited). (Details) - USD ($) $ / shares in Units, $ in Millions	Dec. 30, 2016	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Unusual or Infrequent Item, or Both [Line Items]
Net revenues		$ 1,286.1	$ 1,221.7	$ 1,171.6	$ 1,113.6	$ 1,091.2	$ 1,092.9	$ 1,044.7	$ 994.1	$ 4,793		$ 4,222.9		$ 4,200.6
Net income		386.6	404.2	390	400.4	366.8	362.7	211.2	313.3	1,581.2	[1]	1,254	[1]	1,223	[1]
Net income attributable to T. Rowe Price Group		$ 347.1	$ 390.9	$ 373.9	$ 385.9	$ 379.8	$ 327.8	$ 203.3	$ 304.1	$ 1,497.8		$ 1,215		$ 1,223
Basic earnings on common stock (in dollars per share)		$ 1.40	$ 1.59	$ 1.52	$ 1.56	$ 1.53	$ 1.30	$ 0.81	$ 1.21	$ 6.07		$ 4.85		$ 4.74
Diluted earnings per share (in dollars per share)		$ 1.37	$ 1.56	$ 1.50	1.54	1.50	$ 1.28	0.79	$ 1.18	$ 5.97		$ 4.75		$ 4.63
Income tax provision related to the tax law changes		$ 71.1								$ 71.1
Dell appraisal rights matter [Member]
Unusual or Infrequent Item, or Both [Line Items]
Diluted earnings per share (in dollars per share)					$ 0.12	$ 0.24		$ 0.39
Nonrecurring charge related to Dell appraisal rights matter								$ 166.2				$ 166.2
Insurance proceeds	$ 100				$ 50	$ 100
[1]	See note 15 for a supplementary consolidating cash flow schedule.