Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended					6 Months Ended
	Jan. 07, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2016	Jun. 30, 2015
Class of Stock [Line Items]
Share Price	$ 47.50
Aggregate number of shares repurchased during the period							3,100,000
MaxAmountOfTenderOfferForRepurchaseOfShares				$ 125,000
Repurchase of common stock (shares)	3,013,531
payments for repurchase of common stock excluding transaction costs	$ 143,100
Transaction Costs Related to Tender Offer	$ 1,100
Long-term debt		$ 104,400		$ 0			$ 104,400
Stock Repurchase Program, Number of Shares Authorized to be Repurchased		1,000,000					1,000,000
Shares repurchased under the program (in shares)							0
Shares withheld for tax withholding obligations for the vesting of restricted stock awards (in shares)							100,595
Authorized to repurchased additional shares under repurchase program (in shares)		1,524,332					1,524,332
Dividends declared per share of common stock (in dollars per share)		$ 0.25	$ 0.22		$ 0.22	$ 0.19
Payments of Dividends							$ 9,997	$ 10,407
Minimum [Member]
Class of Stock [Line Items]
Share Price				$ 43.50
Maximum [Member]
Class of Stock [Line Items]
Share Price				$ 50.00