Convertible Senior Notes - Additional Information (Details) $ / shares in Units, shares in Millions | 1 Months Ended | 3 Months Ended | 6 Months Ended | 9 Months Ended | |
Oct. 31, 2014USD ($) | Sep. 30, 2014USD ($) | Jun. 30, 2015USD ($)$ / sharesshares | Jun. 30, 2015USD ($)d$ / sharesshares | Sep. 30, 2014USD ($) | Dec. 31, 2014USD ($) |
Debt Instrument [Line Items] | | | | | | | |
Amortization of discount on convertible notes | | | | | $ 33,644,000 | | |
Convertible notes | | | | $ 1,414,896,000 | $ 1,414,896,000 | | $ 1,376,020,000 |
Exercise price of the warrants | $ / shares | | | | $ 105.28 | $ 105.28 | | |
Convertible Notes | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Initial purchasers' discount | | | $ 28,300,000 | | | $ 28,300,000 | |
Debt issuance costs | | | | | | 500,000 | |
Proceeds from offerings, net of transaction costs | | | 1,860,000,000 | | | | |
Debt Instrument, frequency of periodic payment | | | | | semi-annually | | |
Debt Instrument, date of first required payment | | | | | Mar. 15, 2015 | | |
Debt Instrument Payment Terms | | | | | The interest rates are fixed at 0.25% and 1.00% per annum, respectively, and are payable semi-annually in arrears on March 15 and September 15 of each year, commencing on March 15, 2015. | | |
Amortization of debt discount allocated to interest expense | | | | $ 1,300,000 | $ 2,600,000 | | |
Accrued coupon interest expense | | | | 3,000,000 | $ 6,000,000 | | |
Price percentage for repurchase of notes if repurchase option is elected | | | | | 100.00% | | |
Equity component of the convertible note issuance, net | | | | | $ 100,000 | | |
Amortization of discount on convertible notes | | | | $ 400,000 | $ 400,000 | | |
Number of shares authorized for repurchase under hedge agreement | shares | | | | 24.3 | 24.3 | | |
Exercise price of the option to repurchase stock | $ / shares | | | | | $ 77.64 | | |
Purchases of convertible note hedges | | | | | $ 407,200,000 | | |
Number of warrants issued | shares | | | | 24.3 | 24.3 | | |
Exercise price of the warrants | $ / shares | | | | $ 105.28 | $ 105.28 | | |
Proceeds from issuance of warrants | | | | | $ 289,300,000 | | |
Convertible Notes | Interest Expense | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Amortization of discount on convertible notes | | | | $ 18,600,000 | $ 36,500,000 | | |
Convertible Notes | Scenario One | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Convertible debt instrument, consecutive trading days threshold | | | | | 30 days | | |
Convertible debt instrument, percentage of conversion price to trigger conversion to common stock | | | | | 130.00% | | |
Convertible Notes | Scenario One | Minimum | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Convertible debt instrument, trading days threshold | d | | | | | 20 | | |
Convertible Notes | Scenario Two | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Convertible debt instrument, trading days threshold | d | | | | | 5 | | |
Convertible debt instrument, consecutive trading days threshold | | | | | 5 days | | |
Convertible debt instrument, percentage of conversion price to trigger conversion to common stock | | | | | 98.00% | | |
Convertible Notes | Common Stock | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Debt instrument, conversion principal amount | | | | | $ 1,000 | | |
Debt Instrument, conversion ratio | | | | | 12.8793 | | |
Conversion Price | $ / shares | | | | $ 77.64 | $ 77.64 | | |
Debt Instrument, terms of conversion | | | | | Each $1,000 of principal of these Notes will initially be convertible into 12.8793 shares of the Company’s common stock, which is equivalent to an initial conversion price of approximately $77.64 per share, subject to adjustment upon the occurrence of specified events. | | |
Convertible Notes | Senior Notes Due 2019 | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Debt instrument, principal amount | | | 900,000,000 | $ 935,000,000 | $ 935,000,000 | 900,000,000 | 935,000,000 |
Proceeds from Issuance of Debt | | $ 35,000,000 | | | | | |
Initial purchasers' discount | [1] | | | $ 203,897,000 | $ 203,897,000 | | 225,104,000 |
Debt Instrument, percentage | | | | 0.25% | 0.25% | | |
Debt Instrument, conversion earliest date | | | | | Mar. 15, 2019 | | |
Carrying amount of the equity component | [2] | | | $ 222,826,000 | $ 222,826,000 | | 222,826,000 |
Effective interest rate for amortization to interest expense | | | | 5.75% | 5.75% | | |
Convertible notes | | | | $ 731,103,000 | $ 731,103,000 | | 709,896,000 |
Remaining period for convertible debt | | | | | 50 months | | |
Convertible Notes | Senior Notes Due 2021 | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Debt instrument, principal amount | | | $ 900,000,000 | 954,000,000 | $ 954,000,000 | $ 900,000,000 | 954,000,000 |
Proceeds from Issuance of Debt | | $ 54,000,000 | | | | | |
Initial purchasers' discount | [1] | | | $ 270,207,000 | $ 270,207,000 | | 287,876,000 |
Debt Instrument, percentage | | | | 1.00% | 1.00% | | |
Debt Instrument, conversion earliest date | | | | | Mar. 15, 2021 | | |
Carrying amount of the equity component | [2] | | | $ 283,283,000 | $ 283,283,000 | | 283,283,000 |
Effective interest rate for amortization to interest expense | | | | 6.25% | 6.25% | | |
Convertible notes | | | | $ 683,793,000 | $ 683,793,000 | | $ 666,124,000 |
Remaining period for convertible debt | | | | | 74 months | | |
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[1] | Included in the consolidated balance sheets within convertible notes and amortized over the remaining lives of the Notes. | |
[2] | Included in the consolidated balance sheets within additional paid-in capital. | |