Stock Compensation - Restricted Stock Award and Stock Option Transactions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted Stock Awards (RSAs)
Restricted stock awards, shares activity
Outstanding at the beginning of the period (in shares)	2,639,663	3,536,175	3,273,086
Granted (in shares)	763,446	583,388	899,000
Forfeited/cancelled (in shares)	(234,974)	(577,020)	(230,486)
Vested (in shares)	(878,689)	(902,880)	(405,425)
Outstanding at the end of the period (in shares)	2,289,446	2,639,663	3,536,175	3,273,086
Restricted Stock Awards, Weighted-Average Grant Date Fair Value
Outstanding at the beginning of the period (in dollars per share)	$ 13.65	$ 12.81	$ 13.09
Granted (in dollars per share)	21.65	16.47	12.13
Forfeited/cancelled (in dollars per share)	15.12	11.38	13.59
Vested (in dollars per share)	12.24	13.65	13.10
Outstanding at the end of the period (in dollars per share)	$ 16.70	$ 13.65	$ 12.81	$ 13.09
Stock Options
Stock Options, Shares Activity
Outstanding at the beginning of the period (in shares)	366,000	404,000	1,379,000
Granted (in shares)	0	0	0
Exercised (in shares)	(366,000)	(38,000)	(857,000)
Forfeited/canceled (in shares)	0	0	(118,000)
Vested (in shares)	0	0	0
Outstanding at the end of the period (in shares)	0	366,000	404,000	1,379,000
Stock Options, Weighted-average Remaining Contractual Life
Weighted-average Remaining Contractual Life	0 days	22 days	1 year 22 days	2 years 2 months 1 day
Stock Options, Weighted-average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 15.75	$ 15.75	$ 14.07
Granted (in dollars per share)	0.00	0.00	0.00
Exercised (in dollars per share)	15.75	15.75	13.04
Forfeited/canceled (in dollars per share)	0.00	0.00	15.75
Vested (in dollars per share)	0.00	0.00	0.00
Outstanding at the end of the period (in dollars per share)	$ 0.00	$ 15.75	$ 15.75	$ 14.07