Earnings per Share Earnings per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)									$ 50,789	$ 151,423	$ 13,347
Preferred Stock Dividends									(4,875)	(3,656)	0
Excess of fair value over book value of preferred shares redeemed									0	(2,190)	0
Net Income (Loss) Available to Common Stockholders	9,767	12,399	12,335	11,413	13,043	124,092	6,045	2,397	45,914	145,577	13,347
Net income (loss) available to common shareholders									49,448	150,695	13,347
Basic Weighted Average Shares Outstanding	24,489	24,474	24,470	24,417	24,358	24,358	24,271	22,273	24,463	23,822	19,651
Stock option awards									222	237	92
Deferred compensation awards									142	123	148
Diluted Weighted Average Shares Outstanding	29,944	29,921	29,913	29,870	29,783	29,745	24,646	22,688	29,912	28,763	19,891
Earnings Per Share, Basic	$ 0.40	$ 0.51	$ 0.50	$ 0.47	$ 0.54	$ 5.09	$ 0.25	$ 0.11	$ 1.88	$ 6.11	$ 0.68
Earnings Per Share, Diluted	$ 0.36	$ 0.44	$ 0.44	$ 0.41	$ 0.48	$ 4.22	$ 0.25	$ 0.11	$ 1.65	$ 5.24	$ 0.67
Anti-dilutive stock equivalent awards not included in the calculation of diluted loss per share									1,250	963	1,538
2018 Convertible Senior Notes [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Interest on 3.25% convertible senior subordinated notes due 2017									2,030	2,675	0
Convertible senior subordinated notes potential shares									2,669	2,165	0
2017 Convertible Senior Notes [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Interest on 3.25% convertible senior subordinated notes due 2017									$ 1,504	$ 2,443	$ 0
Convertible senior subordinated notes potential shares									2,416	2,416	0