Common Stock - Cumulative Number of Shares Repurchased (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended
	Jan. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounts payable and accrued expenses		$ 67,255				$ 14,219
Share Repurchase Program (SRP) | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, cumulative repurchases (shares)	67,787				0
Repurchases during the period (shares)		28,264	30,121	9,402	0
Ending balance, cumulative repurchases (shares)		67,787
Beginning balance, cumulative repurchases (usd per share)	$ 23.87				$ 0.00
Repurchases during the period (usd per share)		$ 23.44	$ 24.04	$ 24.67	$ 0.00
Ending balance, cumulative repurchases (usd per share)		$ 23.87
Percent of weighted average number of common stock outstanding permitted for repurchase (percent)		1.00%
Accounts payable and accrued expenses		$ 600
Number of shares not accepted for repurchase (in shares)		64,454
Shares not accepted for repurchase, value		$ 1,500
Shares not accepted for repurchase, average cost per share (in dollars per share)		$ 23.48
Subsequent event | Share Repurchase Program (SRP) | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchases during the period (shares)	28,264
Repurchases during the period (usd per share)	$ 23.44