Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stockholders' Equity Note [Abstract]
Repurchase of treasury stock (in shares)										1,244,433	580,804
Shares withheld for tax withholding obligations for the vesting of restricted stock awards (in shares)										114,523	112,458
Remaining number of shares authorized to be repurchased (in shares)		524,332								524,332
Payments of Dividends [Abstract]
Dividends declared per share of common stock (in dollars per share)		$ 0.22	$ 0.22	$ 0.22	$ 0.19		$ 0.19	$ 0.19	$ 0.17
Special dividends declared, per share of commong stock (in dollars per share)		$ 0.00				$ 2.00
Payments of Ordinary Dividends, Common Stock										$ 21,153	$ 69,493	$ 17,386
Special dividend											$ 50,700		$ 25,700
Total regular and special quarterly dIvidend declared, per share of common stock (in dollars per share)	[1]					$ 2.19
Class of Stock [Line Items]
Preferred stock, authorized (in shares)		20,000,000				20,000,000				20,000,000	20,000,000
Common stock purchase right per preferred stock share (in shares)										1
Series A Junior Participating Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, authorized (in shares)		600,000								600,000

[1] 1) Includes a $2.00 per share special dividend