Options and Awards Options Outstanding Rollforward (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Options outstanding January 1,	5,176	5,448	5,532
Weighted average exercise price January 1,	$ 11.62	$ 10.36	$ 8.51
Options vested January 1,	2,704	2,526	2,218
Weighted Average Exercise Price of Options Vested January 1,	$ 8.18	$ 6.35	$ 4.70
Options Granted	481	497	637
Weighted Average Exercise Price, Options Granted	$ 20.31	$ 19.43	$ 23.27
Options Forfeited in Period	(178)	(127)	(233)
Weighted Average Exercise Price, Options Forfeited in Period	$ 15.82	$ 14.46	$ 12.55
Options Exercised in Period	(740)	(642)	(488)
Weighted Average Exercise Price, Options Exercised in Period	$ 6.93	$ 6.47	$ 5.20
Options outstanding December 31,	4,739	5,176	5,448
Weighted average exercise price December 31,	$ 13.08	$ 11.62	$ 10.36
Options vested December 31,	2,776	2,704	2,526
Weighted Average Exercise Price of Options Vested December 31,	$ 10.07	$ 8.18	$ 6.35