Fair Value of Financial Instruments - Rollforward of Balance Sheet Amounts Within Level 3 Valuation Hierarchy (Details) - Recurring - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Other liabilities
Assets measured on recurring basis, unobservable input reconciliation, calculation [Roll Forward]
Fair value, beginning of period	$ 0	$ 0	$ 0	$ 0
Total realized gains included in income	0	0	0	0
Changes in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at June 30	0	0	0	0
Acquired	0	0	0	0
Purchases	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers out of Level 3	0	0	0	0
Fair value, end of period	0	0	0	0
Total realized gains included in income related to financial assets and liabilities still on the consolidated balance sheet at June 30	0	0	0	0
Other assets
Assets measured on recurring basis, unobservable input reconciliation, calculation [Roll Forward]
Fair value, beginning of period	10,492	10,128	10,478	9,764
Total realized gains included in income	240	159	437	336
Changes in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at June 30	0	0	0	0
Acquired	17,062	0	17,062	0
Purchases	649	246	769	571
Issuances	0	0	0	0
Settlements	(593)	(152)	(896)	(290)
Transfers out of Level 3	0	0	0	0
Fair value, end of period	27,850	10,381	27,850	10,381
Total realized gains included in income related to financial assets and liabilities still on the consolidated balance sheet at June 30	$ 240	$ 159	$ 437	$ 336