Income Taxes - Provision for income taxes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current:
Federal									$ 319	$ 770	$ (27,918)
State and local									(3,102)	365	1,185
Total									(2,783)	1,135	(26,733)
Tax benefits of compensation plans allocated to additional paid-in capital									0	7,553	6,946
Total current income tax provision									(2,783)	8,688	(19,787)
Deferred federal									15,467	18,023	16,637
Deferred other									1,334	1,943	3,110
Deferred total									16,801	19,966	19,747
Deferred tax allocated to other comprehensive income (loss)									(21,866)	(11,669)	(9,961)
Total deferred income tax provision									(5,065)	8,297	9,786
(Benefit) provision for income taxes	$ (562)	$ (3,047)	$ 711	$ (4,950)	$ 13,561	$ 2,148	$ 4,305	$ (3,029)	$ (7,848)	$ 16,985	$ (10,001)