Stockholders' Equity - Repurchase Program (Details) - USD ($)		3 Months Ended	6 Months Ended
	Feb. 04, 2016	Jun. 30, 2016	Jun. 30, 2016	Jun. 30, 2015
Class of Stock [Line Items]
Shares repurchased (in shares)		191,291	191,291
Repurchase of common stock		$ (26,000,000)	$ (26,037,000)	$ 0
Common Stock [Member]
Class of Stock [Line Items]
Stock repurchase program, approved amount	$ 500,000,000
Stock repurchase program, authorized time period	18 months