Fair Value Measurement (Changes in Level 3 Table) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale securities, Beginning balance	$ 212,512		$ 48,096		$ 49,661		$ 87,539
True-up liability, Beginning balance	10,937		11,820		12,259		11,551
Fair value of assets acquired	0	[1]		[1]	3,271	[1]	0	[1]
Available-for-sale securities, Total unrealized gains/losses	0	[1]	0	[1]	0	[1]	0	[1]
True-up liability, Total unrealized gains/losses	520	[1]	822	[1]	0	[1]	1,091	[1]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	(1,704)	[2]	(605)	[2]	(2,066)	[2]	3,137	[2]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss)		[2]	0	[2]	(802)	[2]	0	[2]
Available-for-sale securities, Purchases	111,940		0		271,856		0
True-up liability, Purchases	0		0		0		0
Available-for-sale securities, Sales	0		0		0		(40,520)
True-up liability, Sales	0		0		0		0
Available-for-sale securities, Settlements	13		13		39		(2,652)
True-up liability, Settlements	0		0		0		0
Available-for-sale securities, Transfers	0		0		0		0
True-up liability, Transfers	0		0		0		0
Available-for-sale securities, Ending balance	322,761		47,504		322,761		47,504
True-up liability, Ending balance	$ 11,457		$ 12,642		$ 11,457		$ 12,642

[1] (a) Reported in other expense

[2] (b) Reported in other comprehensive income (loss)