Earnings (Loss) Per Share (Basic and Diluted Earnings (Loss) Per Common Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Earnings Per Share [Abstract]
Net income (loss) attributable to common stockholders - Basic																	$ 49,791		$ 26,540		$ (50,008)
Impact of assumed conversions:
Interest on convertible notes																	1,959		0		0
Dividends on preferred stock																	0		141		0
Net income (loss) attributable to common stockholders - Diluted																	$ 51,750		$ 26,681		$ (50,008)
Weighted average common shares outstanding - Basic																	48,185		44,229		25,731
Assumed conversions:
Incremental common shares from warrants																	1,560		2,222		0
Incremental common shares from stock options																	992		747		0
Incremental common shares from convertible preferred stock before conversion																	0		440		0
Incremental common shares from restricted stock units																	116		0		0
Incremental common shares from convertible senior notes																	2,701		0		0
Weighted average common shares outstanding - Diluted																	53,554		47,638		25,731
Basic earnings (loss) per common share	$ 0.48	[1]	$ 0.20	[1]	$ 0.27	[1]	$ 0.08	[1]	$ 0.02	[1]	$ 0.38	[1]	$ 0.05	[1]	$ 0.15	[1]	$ 1.03	[1]	$ 0.60	[1]	$ (1.94)
Diluted earnings (loss) per common share	$ 0.44	[1]	$ 0.19	[1]	$ 0.25	[1]	$ 0.07	[1]	$ 0.02	[1]	$ 0.35	[1]	$ 0.04	[1]	$ 0.13	[1]	$ 0.97	[1]	$ 0.56	[1]	$ (1.94)

[1] The sum of the quarterly earnings per share applicable to common stockholders (basic and diluted) may not agree to the earnings per share for the year due to the timing of common stock issuances.