Stock-Based Compensation - Schedule of Stock Appreciation Rights (Details) - Stock Appreciation Rights - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Summary of Stock Appreciation Rights Activity (in shares)
Outstanding at beginning of period (in shares)	667,764	667,764	1,722,444
Granted (in shares)		0	0
Exercised (in shares)	(109,218)	0	(1,054,680)
Forfeited (in shares)	0	0	0
Outstanding at end of period (in shares)	558,546	667,764	667,764
Exercisable at end of period (in shares)	558,546	590,960	386,582
Weighted-Average Exercise Price (in dollars per share)
Outstanding at beginning of period (in USD per share)	$ 12.63	$ 12.63	$ 9.75
Granted (in USD per share)		0.00	0.00
Exercised (in USD per share)	13.19	0.00	7.92
Forfeited (in USD per share)	0.00	0.00	0.00
Outstanding at end of period (in USD per share)	12.52	12.63	12.63
Exercisable at end of period (in USD per share)	$ 12.52	$ 11.98	$ 11.33
Additional disclosures
Aggregate intrinsic value	$ 2.9
Weighted-average remaining contractual term of non-vested shares	2 years 2 months 28 days
Aggregate intrinsic value of stock appreciation rights exercisable	$ 2.9
Stock appreciation rights exercisable, weighted average remaining contractual term	2 years 2 months 28 days