Stockholders' Equity - Share Repurchase Program (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2011
Equity [Abstract]
Common stock repurchase authorization amount available			$ 98,100,000
Common stock repurchase authorized amount				150,000,000.0
Common stock repurchased and retired, shares	171,263	1,507,659
Common stock repurchased and retired, weighted average price per share	$ 45.54	$ 29.96
Common stock repurchased and retired, total value	$ 7,800,000	$ 45,200,000