Earnings per Share (Summary of Basic and Diluted Earnings per Share Footnote) (Details)	3 Months Ended		12 Months Ended
	Dec. 31, 2013		Dec. 31, 2014		Dec. 31, 2013
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted average shares outstanding-diluted	36,794,215	[1]	37,133,584	[1]
Operating Partnership [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted average shares outstanding-diluted					7,797,000
Class A Units [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted average shares outstanding-diluted			7,770,000
Class O Units [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted average shares outstanding-diluted			195,000		24,000
Class RS Units [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted average shares outstanding-diluted			7,770,000
Options to purchase Class A common stock [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted average shares outstanding-diluted			114,000

[1] Includes 7,770 Class A and Class RS units, 195 “in the money” value of Class O units on an “as if” converted basis and 114 “in the money” value options to purchase shares of Class A common stock on an “as if” converted basis as of the year ended December 31, 2014. As of the year ended December 31, 2013, this amount includes 7,797 Class A and Class RS units and 24 “in the money” value of Class O units on as “as if” converted basis.