Consolidated Statements of Stockholders' Equity and Comprehensive Income (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common stock	Additional Paid-In Capital	Retained Earnings	Members' Interests Acquired, at Cost
Balances at Dec. 31, 2009	$ 69,811	$ 147	$ 28,508	$ 50,982	$ (9,826)
Balances (in shares) at Dec. 31, 2009		14,741,504
Changes in stockholders' equity
Net income	8,227			8,227
Equity receivables collected	173		173
Cash distributed to Column	(159)		(159)
Distributions to members	(11,828)			(11,828)
Formation transaction including stock split			(9,826)		9,826
Issuance of common stock	58,369	67	58,302
Issuance of common stock (in shares)		6,666,667
Stock-based compensation	49		49
Balances at Dec. 31, 2010	124,642	214	77,047	47,381
Balances (in shares) at Dec. 31, 2010		21,408,171
Changes in stockholders' equity
Net income	34,864			34,864
Issuance of common stock	2,053	2	2,051
Issuance of common stock (in shares)		221,292
Stock-based compensation	2,422		2,422
Issuance of common stock in connection with equity compensation plans	1	1
Issuance of common stock in connection with equity compensation plans (in shares)		157,608
Repurchase and retirement of common stock	(473)		(473)
Repurchase and retirement of common stock (in shares)		(38,473)
Tax benefit from vesting of restricted shares	143		143
Balances at Dec. 31, 2011	163,652	217	81,190	82,245
Balances (in shares) at Dec. 31, 2011	21,748,598	21,748,598
Changes in stockholders' equity
Net income	33,772			33,772
Stock-based compensation	5,176		5,176
Issuance of common stock in connection with equity compensation plans	375	2	373
Issuance of common stock in connection with equity compensation plans (in shares)		220,236
Issuance of common stock in connection with the acquisition of CWCapital LLC	150,698	117	150,581
Issuance of common stock in connection with the acquisition of CWCapital LLC (in shares)		11,647,255
Repurchase and retirement of common stock	(741)		(741)
Repurchase and retirement of common stock (in shares)		(48,359)
Tax benefit from vesting of restricted shares	244		244
Balances at Dec. 31, 2012	$ 353,176	$ 336	$ 236,823	$ 116,017
Balances (in shares) at Dec. 31, 2012	33,567,730	33,567,730