Consolidated Statements of Equity (USD $) | Total | Preferred Shares [Member] | Common Shares [Member] | Additional Paid-in Capital [Member] | Accumulated Other Comprehensive Income (Loss) [Member] | Retained Earnings [Member] | Parent [Member] | Noncontrolling Interest [Member] |
In Thousands, except Share data, unless otherwise specified |
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2011 | $1,116,348 | $90 | $508 | $1,142,905 | | ($30,252) | $1,113,251 | $3,097 |
Preferred Stock, Shares Outstanding at Dec. 31, 2011 | | 9,000,000 | | | | | | |
Common Stock, Shares, Outstanding at Dec. 31, 2011 | | | 50,769,024 | | | | | |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | | | | | | | | |
Issuance of shares, net of offering costs, Shares | | | 9,544,087 | | | | | |
Issuance of shares, net of offering costs, Value | 211,520 | | 95 | 211,425 | | | 211,520 | |
Issuance of Common Shares for Board Of Trustees Compensation , Shares | | | 10,361 | | | | | |
Issuance of Common Shares for Board Of Trustees Compensation, Value | 199 | | | 199 | | | 199 | |
Repurchase of Common Stock, Shares | | | -15,595 | | | | | |
Repurchase of Common Shares, Value | -319 | | | -319 | | | -319 | |
Share-based Compensation, Shares | | | 48,324 | | | | | |
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures | | | 1 | | | | | |
Share-based Compensation, Value | 2,750 | | | 1,564 | | | 1,565 | 1,185 |
Distributions on Common Shares and Units | -20,810 | | | | | -20,476 | -20,476 | -334 |
Distributions on Preferred Shares | -13,378 | | | | | -13,369 | -13,369 | -9 |
Unrealized gain (loss) on derivative instruments | -389 | | | | -389 | | -389 | |
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest | 19,295 | | | | | 18,991 | 18,991 | 304 |
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Sep. 30, 2012 | 1,315,216 | 90 | 604 | 1,355,774 | | -45,106 | 1,310,973 | 4,243 |
Preferred Stock, Shares Outstanding at Sep. 30, 2012 | | 9,000,000 | | | | | | |
Common Stock, Shares, Outstanding at Sep. 30, 2012 | | | 60,356,201 | | | | | |
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2012 | 1,313,092 | 90 | 610 | 1,362,349 | -300 | -49,798 | 1,312,951 | 141 |
Preferred Stock, Shares Outstanding at Dec. 31, 2012 | 9,000,000 | 9,000,000 | | | | | | |
Common Stock, Shares, Outstanding at Dec. 31, 2012 | 60,955,090 | | 60,955,090 | | | | | |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | | | | | | | | |
Issuance of shares, net of offering costs, Shares | | 4,000,000 | 171,893 | | | | | |
Issuance of shares, net of offering costs, Value | 101,242 | 40 | 2 | 101,200 | | | 101,242 | |
Issuance of Common Shares for Board Of Trustees Compensation , Shares | | | 9,097 | | | | | |
Issuance of Common Shares for Board Of Trustees Compensation, Value | 207 | | | 207 | | | 207 | |
Repurchase of Common Stock, Shares | | | -21,644 | | | | | |
Repurchase of Common Shares, Value | -523 | | | -523 | | | -523 | |
Share-based Compensation, Shares | | | 65,192 | | | | | |
Share-based Compensation, Value | 3,857 | | | 2,672 | | | 2,672 | 1,185 |
Distributions on Common Shares and Units | -29,705 | | | | | -29,522 | -29,522 | -183 |
Distributions on Preferred Shares | -16,881 | | | | | -16,872 | -16,872 | -9 |
Unrealized gain (loss) on derivative instruments | 1,211 | | | | 1,211 | | 1,211 | |
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest | 32,212 | | | | | 32,001 | 32,001 | 211 |
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Sep. 30, 2013 | $1,404,712 | $130 | $612 | $1,465,905 | $911 | ($64,191) | $1,403,367 | $1,345 |
Preferred Stock, Shares Outstanding at Sep. 30, 2013 | 13,000,000 | 13,000,000 | | | | | | |
Common Stock, Shares, Outstanding at Sep. 30, 2013 | 61,179,628 | | 61,179,628 | | | | | |