Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended									12 Months Ended
	Jan. 07, 2016	Dec. 31, 2017		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Nov. 16, 2017
Stockholders' Equity Note [Abstract]
Repurchase of treasury stock (in shares)											594,974	776,126
Shares withheld for tax withholding obligations for the vesting of restricted stock awards (in shares)											305,828	202,670
Additional shares authorized for Repurchase under the Stock Repurchase Program (in shares)															1,000,000
Remaining number of shares authorized to be repurchased (in shares)		2,677,564									2,677,564
MaxAmountOfTenderOfferForRepurchaseOfShares	$ 125,000
Share Price	$ 23.75
Stock Repurchased and Retired During Period, Shares	6,027,062
Repurchase of common stock	$ 143,100											$ 144,263
Transaction Costs Related to Tender Offer	1,100
Long-term debt	$ 104,400	$ 104,400					$ 104,400				$ 104,400	104,400
Payments of Dividends [Abstract]
Dividends declared per share of common stock (in dollars per share)		$ 1.150	[1]	$ 0.150	$ 0.150	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.110
Dividends paid											$ 65,768	$ 20,599	$ 21,153
Class of Stock [Line Items]
Special dividend, per share		$ 1.00
Special dividend		$ 41,700												$ 50,700
Preferred stock, authorized (in shares)		20,000,000					20,000,000				20,000,000	20,000,000
Preferred Stock, Value, Issued		$ 0					$ 0				$ 0	$ 0

[1] (1) Includes a $1.00 per share special dividend.