Fair Value Measurement (Changes in Level 3 Table) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale securities, Beginning balance	$ 51,234		$ 88,487		$ 49,661		$ 87,539
True-up liability, Beginning balance	12,783		11,725		12,259		11,551
Fair value of assets acquired	3,271	[1]	0	[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	(1,846)	[1]	95	[1]	(1,322)	[1]	269	[1]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	(1,923)	[2]	1,323	[2]	(363)	[2]	3,742	[2]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	[2]	0	[2]	0	[2]	0	[2]
Available-for-sale securities, Purchases	159,916		0		159,916		0
True-up liability, Purchases	0		0		0		0
Available-for-sale securities, Sales	0		(40,520)		0		(40,520)
True-up liability, Sales	0		0		0		0
Available-for-sale securities, Settlements	14		(1,194)		27		(2,665)
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	212,512		48,096		212,512		48,096
True-up liability, Ending balance	$ 10,937		$ 11,820		$ 10,937		$ 11,820

[1] (a) Reported in other expense

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